Ndatenda nekushanyira Nature.com.Uri kushandisa shanduro yebrowser ine tsigiro shoma yeCSS.Kuti uwane ruzivo rwakanyanya, tinokurudzira kuti ushandise browser yakagadziridzwa (kana kudzima Compatibility Mode muInternet Explorer).Pamusoro pezvo, kuti tive nechokwadi chekutsigira kunoenderera, tinoratidza saiti isina masitaera uye JavaScript.
Inoratidza carousel yemasiraidhi matatu panguva imwe chete.Shandisa mabhatani ePashure neAnotevera kufamba nemasiraidhi matatu panguva, kana kushandisa mabhatani anotsveyamisa ari kumagumo kufamba nemasiraidhi matatu panguva.
Dhizaini uye kusimudzira kwepamusoro pekuita catalysts yakagamuchira tarisiro huru mukusarudza hydrogenation maitiro asi inoramba iri dambudziko guru.Pano isu tinoshuma monatomic RuNi alloy (SAA) umo maatomu eRu anovharirwa pamusoro peNi nanoparticles kuburikidza neRu-Ni coordination, iyo inoperekedzwa ne electron transfer kubva pasi pepasi Ni kuenda kuRu.Kuziva kwedu, yakanakisa catalyst 0.4% RuNi SAA panguva imwe chete yakaratidza basa repamusoro (TOF kukosha: 4293 h-1) uye chemoselectivity yekusarudza hydrogenation ye4-nitrostyrene kusvika 4-aminostyrene (goho:> 99%), iyo yepamusoro-soro ne. zvichienzaniswa neanozivikanwa heterogeneous catalysts.In situ zviedzo uye kuverenga kwemaoretical kunoratidza kuti nzvimbo dzeRu-Ni interface, senzvimbo dzemukati dzinoshanda, dzinokurudzira kuputswa kweNO bonds ine simba rezasi re0.28 eV.Mukuwedzera, synergistic Ru-Ni catalysis inofarira kuumbwa kwepakati (C8H7NO * uye C8H7NOH *) uye inokurumidzira danho rekugadzirisa chiyero (hydrogenation yeC8H7NOH *).
Functionalized anonhuwirira amines, akakosha ekuvaka emakemikari akanaka, ane akakosha maindasitiri ekushandisa mukugadzirwa kwemishonga, agrochemicals, pigment uye mapolymers1,2,3.Iyo catalytic hydrogenation yeinowanikwa nyore nyore nitroaromatic makomisheni pamusoro peanosiyana catalysts yakwezva kutarisisa kukuru senzira ine ushamwari kwezvakatipoteredza uye inogona kudzokororwa yekugadzira maamine ane yakawedzera kukosha4,5,6,7.Nekudaro, iyo chemoselective kuderedzwa kwe-NO2 mapoka uchichengeta mamwe mapoka anodzikiswa akadai sealkenes, alkynes, halogens, kana ketones ibasa rinodiwa zvikuru asi rinonetsa8,9,10,11.Nokudaro, kushandiswa kwehungwaru kwehuterogeneous catalysts nokuda kwekuderedzwa kwakananga kwe -NO2 mapoka pasina kukanganisa zvimwe zvisungo zvinogadziriswa zvinodikanwa zvikuru12,13,14.Mazhinji emhando-yesimbi-isina catalysts akaferefetwa kuti akonzerese iyo hydrogenation ye nitroarenes, asi hutsinye hwekuita mamiriro anodzivirira kushandiswa kwavo kwakakura15,16.Kunyangwe zvigadziriso zvesimbi zvemhando yepamusoro (seRu17, Pt18, 19, 20 kana Pd21, 22, 23) zviri kushanda pasi pemamiriro ezvinhu akapfava, anowanzo tambura nemutengo mukuru, suboptimal selectivity, uye kushandiswa kwakaderera kweatomu.Nekudaro, kuwana yakanyanya kushanda uye chemoselective catalysts neane dhizaini uye nekugadzirisa kwakanaka kwechimiro chakanaka chinoramba chiri dambudziko guru24,25,26.
Monatomic Alloy (SAA) catalysts ine yakanyanya kunaka simbi inoshanda, yakakosha geometric uye yemagetsi chimiro, inopa yakasarudzika nzvimbo dzinoshanda, uye inopa yakanakisa mashandiro ekuita nekutyora hunhu mutsara kuyera maitiro27,28,29,30,31.Yakaiswa maatomu mamwechete uye maatomu esimbi anotambira muSAA anogona kushanda senzvimbo mbiri dzinoshanda, kufambisa kuvhurwa kweatomu akawanda kana kubvumira matanho ekutanga ekuita kuti aitike panzvimbo dzakasiyana32,33,34.Pamusoro pezvo, kushamwaridzana kweheterometallic pakati peatomu yesimbi isina kuchena uye simbi inogashira inogona kutungamira kune idiosyncratic synergistic mhedzisiro, kunyangwe kunzwisiswa kweiyo synergistic mhedzisiro pakati pemaseti maviri enzvimbo dzesimbi paatomu level inoramba ichinetsa35,36,37,38.Kune iyo hydrogenation yeinoshanda nitroarenes, iyo yemagetsi uye geometric zvimiro zveanoshanda nzvimbo dzinofanirwa kugadzirwa nenzira yekumhanyisa kuita activation yemapoka e nitro chete.Sezvo mutemo, mapoka e-electron-deficient nitro anonyanya kudsorbed pamatunhu nucleophilic e-catalyst surface, asi mune inotevera hydrogenation nzira, cooperative catalysis yenzvimbo dzakavakidzana dzinoshanda dzichaita basa rinokosha mukudzora reactivity uye chemoselectivity4,25.Izvi zvakaita kuti tiongorore zvinokonzeresa zveSAA semumiriri anovimbisa kuvandudza kugona kwechemoselective hydrogenation yenitroaromatic compounds, pamwe nekuwedzera kujekesa hukama pakati peinoshingaira saiti chimiro uye atomic scale catalytic performance.
Pano, catalysts yakavakirwa pamonatomic RuNi alloys yakagadziridzwa zvichienderana nematanho maviri ekugadzira nzira, kusanganisira structural-topological shanduko ye layered double hydroxide (LDH) inoteverwa neelectro-displacement treatment.RuNi SAA inoratidzira hunyanzvi hwekuita (> 99% goho) kune chemoselective hydrogenation ye4-nitrostyrene kusvika 4-aminostyrene ine turnover frequency (TOF) inosvika ~4300 mol-mol Ru-1 h-1, inova yakanyanya mwero pakati pezvakasiyana-siyana catalysts zvakanyoreswa pasi pemamiriro ekuita akafanana.Electron microscopy uye spectroscopic characterization yakaratidza kuti maatomu eRu ari ega akapararira pamusoro peNi nanoparticles (~ 8 nm), achigadzira kugadzikana kweRu-Ni, zvichikonzera kusarudzika nzvimbo dzeRu (Ruδ-) nekuda kwekufambiswa kweelectron kubva pasi peNi kuenda kuRu. .In situ FT-IR, XAFS zvidzidzo uye density functional theory (DFT) kuverenga kwakasimbisa kuti masaiti ari paRu-Ni interface senzvimbo dzemukati dzinoshanda dzinofambisa nitro.Activated adsorption (0.46 eV) inosiyana kubva kune iyo monometallic nickel catalyst.(0.74 eV).Mukuwedzera, hydrogen dissociation inoitika munzvimbo dzakapoteredza Ni, inoteverwa nehydrogenation yepakati (C8H7NO * uye C8H7NOH *) munzvimbo dzeRuδ.Iyo synergistic mhedzisiro yerutsigiro doping muRuNi SAA catalyst inoguma yakasarudzika nitroarenes hydrogenation chiitiko uye sarudzo, iyo inogona kuwedzeredzwa kune isingawanzo yakasarudzika simbi catalysts inoshandiswa mukugadzirisa maitiro ekuita.
Zvichienderana neshanduko yeiyo structural topology ye layered double hydroxide (LDH) precursors, takagadzirira monometallic Ni yakaiswa pane amorphous Al2O3 substrates.Mushure meizvozvo, seti yeRuNi/Al2O3 bimetallic samples ine akasiyana Ru content (0.1-2 wt %) yakanyatsogadzirwa ne electrodisplacement kuisa Ru maatomu pamusoro peNi nanoparticles (NPs) (Fig. 1a).Inductively yakasanganiswa plasma atomic emission spectrometry (ICP-AES) zviyero zvakapa zvakajeka kuumbwa kweRu neNi mune aya masampuli (Supplementary Tafura 1), iri padyo neiyo theoretical feedstock kurodha.Iyo SEM mifananidzo (Supplementary Figure 1) uye BET mhedzisiro (Supplementary Figures 2-9 uye Supplementary Tafura 1) inoratidza zvakajeka kuti morphological chimiro uye chaiyo nzvimbo yeiyo RuNi/Al2O3 samples haiitike shanduko dziri pachena panguva yekurapa kwe electrochemical.- nzira yekufamba.Iyo X-ray pateni (Fig. 1b) inoratidza nhevedzano yemaitiro ekuratidzira pa2θ 44.3 °, 51.6 °, uye 76.1 °, inoratidza zvikamu (111), (200), uye (220) yemazuva ese Ni (JCPDS 004-0850). )Zvikurukuru, iwo maSamples eRuNi haaratidze maratidziro esimbi kana oxidized Ru, zvichiratidza kupararira kwakanyanya kweRu mhando.Transmission electron microscopy (TEM) zviyero zve monometallic Ni uye RuNi samples (Fig. 1c1-c8) inoratidza kuti nickel nanoparticles yakanyatsoparadzirwa uye haigadziriswi pane amorphous Al2O3 tsigiro ine zvidimbu zvakafanana (7.7-8.3 nm).Mifananidzo yeHRTEM (Figs. 1d1-d8) inoratidza nguva yeuniform lattice inenge 0.203 nm muNi uye RuNi samples, inofananidzwa neNi (111) ndege, zvisinei, mapeji emarara eRu particles haasipo.Izvi zvinoratidza kuti maatomu eRu akaparadzirwa zvakanyanya pamuenzaniso wepamusoro uye haakanganisa nguva yeNi lattice.Zvichakadaro, 2 wt% Ru / Al2O3 yakagadziriswa nedeposition-deposition method sekutonga, umo masumbu eRu akagoverwa zvakafanana pamusoro peAl2O3 substrate (Supplementary Figs. 10-12).
a Scheme of the synthesis route for RuNi/Al2O3 samples, b X-ray diffraction mapatani eNi/Al2O3 uye akasiyana eRuNi/Al2O3 samples.c1−c8 TEM uye d1−d8 HRTEM grating mifananidzo ine inosiyana particle size kugoverwa kwe monometallic Ni, 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0, 8% wt., 1 wt.Mufananidzo une mitsetse.% uye 2 wt.% RuNi."au" zvinoreva zvikamu zvisingaite.
Iyo catalytic chiitiko cheRuNi samples yakadzidzwa ne chemoselective hydrogenation ye4-nitrostyrene (4-NS) kusvika 4-aminostyrene (4-AS).Iyo 4-NS kutendeuka pane yakachena Al2O3 substrate yaingova 0.6% mushure meawa 3 (Supplementary Table 2), zvichiratidza zvishoma zvinokonzeresa mhedzisiro yeAl2O3.Sezvinoratidzwa mufig.2a, iyo yepakutanga nickel catalyst yakaratidza yakaderera zvakanyanya kuita basa ne4-NS shanduko ye7.1% mushure memaawa matatu, nepo 100% kutendeuka kwaigona kuwanikwa pamberi peiyo monometallic Ru catalyst pasi pemamiriro akafanana.Zvose zveRuNi catalysts zvakaratidza zvakanyanya kuwedzera hydrogenation basa (kutendeuka: ~ 100%, 3 h) zvichienzaniswa nemuenzaniso wemonometallic, uye chiyero chekuita chakanga chakanyatsobatanidzwa neRu content.Izvi zvinoreva kuti Ru zvimedu zvinotamba basa rakasimba mukuita kwehydrogenation.Sezvineiwo, chigadzirwa selectivity (Fig. 2b) inosiyana zvikuru zvichienderana nechinokonzera.Kune iyo isingashande yakachena nickel catalyst, chigadzirwa chikuru chaive 4-nitroethylbenzene (4-NE) (selectivity: 83.6%) uye kusarudzwa kwe4-AC kwaive 11.3%.Panyaya ye monometallic Ru, C = C bond mu 4-NS inonyanya kukonzerwa nehydrogenation kupfuura -NO2, zvichiita kuti pave ne 4-nitroethylbenzene (4-NE) kana 4-aminoethyl benzene (4-AE);iyo selectivity ye4-AC yaingova 15.7%.Zvinoshamisa kuti, RuNi catalysts ine zvishoma zvishoma Ru content (0.1-0.4 wt%) yakaratidza yakanakisa selectivity (> 99%) kusvika 4-aminostyrene (4-AS), zvichiratidza kuti NO2 uye kwete vinyl, yakasiyana-siyana chemoselective.Apo zvinyorwa zveRu zvakapfuura 0.6 wt.%, kusarudzwa kwe4-AS kwakaderera zvakanyanya nekuwedzera kwekutakura kweRu, asi kusarudzwa kwe4-AE kwakawedzera panzvimbo.Kune iyo catalyst ine 2 wt% RuNi, ese ari nitro uye vinyl mapoka aive akanyanya hydrogenated ane high selectivity ku4-AE ye98%.Kuti udzidze maitiro eRu dispersion state pane catalytic reaction, 0.4 wt% Ru/Al2O3 samples dzakagadzirirwa (Supplementary Figures 10, 13 uye 14) umo maRu particles ainyanya kuparadzirwa semaatomu ega achiteverwa nemasumbu mashoma eRu.(quasi-atomic Ru).The catalytic performance (Supplementary Table 2) inoratidza kuti 0.4 wt% Ru / Al2O3 inovandudza 4-AS selectivity (67.5%) yakaenzaniswa ne2 wt% Ru / Al2O3 sampuli, asi basa racho rakaderera (kutendeuka: 12.9).%;3 maawa).Zvichienderana nehuwandu hwemasayiti esimbi pamusoro pezviyero zvakatemwa neCO pulsed chemisorption zviyero, iyo turnover frequency (TOFmetal) yeRuNi catalyst yakawanikwa pazasi 4-NS kutendeuka (Supplementary Fig. 15), iyo yakaratidza maitiro ekutanga kuwedzera kuwedzera. uyezve kuderera nekuwedzera kuwedzera kweRu loading (Supplementary Fig. 16).Izvi zvinoratidza kuti hadzisi dzese nzvimbo dzesimbi dzepamusoro dzinoita senzvimbo dzinoshanda dzeRuNi catalysts.Mukuwedzera, iyo TOF yeRuNi catalyst yakaverengwa kubva kuRu nzvimbo kuti iwedzere kuzarura basa rayo remukati catalytic (Fig. 2c).Sezvo zvirimo zveRu zvichiwedzera kubva ku0.1 wt.% kusvika 0.4 wt.% RuNi catalysts yakaratidza inenge inogara TOF values ​​​​(4271-4293 h-1), iyo inoratidza kuwanikwa kweRu particles muatomic dispersion (pamwe nekuumbwa kweRuNi SAA).) uye inoshanda senzvimbo huru inoshanda.Zvisinei, nekuwedzera kwekuwedzera kwekutakura kweRu (mukati me 0.6-2 wt%), kukosha kweTOF kunoderera zvakanyanya, izvo zvinoratidza kuchinja kwemukati wemukati wenzvimbo inoshanda (kubva paatomic dispersion kusvika kuRu nanoclusters).Mukuwedzera, kune ruzivo rwedu, iyo TOF ye 0.4 wt% RuNi (SAA) catalyst iri padanho repamusoro-soro pakati pesimbi catalysts yakambotaurwa pasi pemamiriro akafanana ekuita (Supplementary Table 3), zvichiratidzazve kuti monoatomic RuNi alloys inopa yakanakisa catalytic properties.mutambo.Supplementary Figure 17 inoratidza mashandiro anoita 0.4 wt% RuNi (SAA) catalyst pamatambudziko akasiyana-siyana uye tembiricha yeH2, uko H2 kudzvanywa kwe 1 MPa uye kuita tembiricha ye60 ° C kwakashandiswa seyakanyanya kuita paramita.sampuli ine RuNi 0.4 wt.% (Fig. 2d), uye hapana kuderera kukuru kwekuita uye zvibereko zvakaonekwa pamusoro pezvikamu zvishanu zvakatevedzana.X-ray uye TEM mifananidzo ye0.4 wt% RuNi catalyst yakashandiswa mushure me 5 cycles (Supplementary Figures 18 uye 19) yakaratidza kusachinja kukuru mukugadzirwa kwekristaro, zvichiratidza kugadzikana kwepamusoro kwesarudzo yehydrogenation reaction.Mukuwedzera, iyo 0.4 wt% RuNi (SAA) catalyst inopawo goho rakanaka kwazvo remamines kune chemoselective hydrogenation yemamwe nitroaromatic makomisheni ane halogens, aldehydes, uye hydroxyl mapoka (Supplementary Table 4), ichiratidza kushanda kwayo kwakanaka.
a Catalytic kutendeuka uye b kugovera 4-nitrostyrene hydrogenation zvigadzirwa pamberi pe monometallic Ni, Ru, uye RuNi catalysts ane akasiyana Ru content (0.1-2 wt %), c in the catalytic dynamic range, Turnover frequency (TOF) paRuNi catalysts c zvichienderana neRu per mole.d Muedzo wekugona kushandiswazve kwe0.4 wt.% RuNi catalyst yezvishanu zvakatevedzana catalytic cycles.ln (C0/C) inobva pakuita nguva yehydrogenation ye e-nitrobenzene uye f-styrene ine musanganiswa we nitrobenzene uye styrene (1: 1).Maitiro ekuita: 1 mmol reagent, 8 ml solvent (ethanol), 0.02 g catalyst, 1 MPa H2, 60°C, maawa matatu.Mabhawa ekukanganisa anotsanangurwa seyakajairwa kutsauswa kwematatu akadzokorora.
Kuenderera mberi nekuongorora zvakakosha chemoselective musiyano, hydrogenation yemusanganiswa we styrene uye nitrobenzene (1: 1) yakaitwa pamberi pe monometallic catalysts Ni, Ru, 0.4 wt% RuNi, uye 2 wt% RuNi, zvichiteerana (Supplementary Fig. 20).Kunyange zvazvo chemoselectivity yezvinoitwa hydrogenation yemapoka anoshanda ichienderana, zvechokwadi kune mimwe misiyano mukusarudza kwe intramolecular uye intermolecular hydrogenation nekuda kwema molecular allosteric effects.Sezvinoratidzwa mufig.2e,f, curve ln(C0/C) maringe nenguva yekuita inopa mutsara wakatwasuka kubva kwawakabva, zvichiratidza kuti zvese nitrobenzene ne styrene ndezvekunyepa-kutanga kurongeka.Monometallic nickel catalysts yakaratidza kuderera kwakanyanya kwehydrogenation rate yezvose p-nitrobenzene (0.03 h-1) uye styrene (0.05 h-1).Zvinonyanya kukosha, yakanakira styrene hydrogenation chiitiko (chiyero chekugara: 0.89 h-1) chakawanikwa paRu monometallic catalyst, iyo yakakwirira kudarika nitrobenzene hydrogenation chiitiko (chiyero chisingaperi: 0.18 h-1).Panyaya ye catalyst ine RuNi(SAA) 0.4 wt.% nitrobenzene hydrogenation is dynamically more favourite than styrene hydrogenation (rate constant: 1.90 h-1 vs. 0.04 h-1), zvichiratidza kuda kwe -NO2 boka.pamusoro peC hydrogenation = chisungo C. Nokuda kwekugadzirisa ne 2 wt.% RuNi, chiyero chekugara kwehydrogenation ye nitrobenzene (1.65 h-1) yakaderera kana ichienzaniswa ne0.4 wt.% RuNi (asi ichiri yakakwirira kudarika iyo ye-mono-metal catalyst), nepo hydrogenation rate ye styrene yakawedzera zvakanyanya (chiyero chekugara: 0.68).h−1).Izvi zvinoratidzawo kuti ne synergistic effect pakati peNi naRu, iyo catalytic chiitiko uye chemoselectivity yakananga -NO2 mapoka anowedzera zvakanyanya kuenzaniswa neRuNi SAA.
Kuti utarise mamiriro ekupararira kweRu neNi komputa, nzira yekufungidzira uchishandisa yakakwira-angle mhete yakasviba scanning electron microscopy ine aberration correction (AC-HAADF-STEM) uye element mapping by energy dispersive spectroscopy (EDS) yakaitwa.Iyo EMF elemental mepu yemuenzaniso ine 0.4 wt% RuNi yemukati (Fig. 3a, b) inoratidza kuti Ru yakanyanya kufanana yakapararira pane nickel nanoparticles, asi kwete paAl2O3 substrate, inoenderana AC-HAADF-STEM mufananidzo (Fig. 3c) inoratidza, Zvinogona kuonekwa kuti pamusoro peNi NPs ine mavara mazhinji akajeka ehukuru hweatomu yeRu maatomu (akaiswa miseve yebhuruu), nepo pasina masumbu kana Ru nanoparticles anocherechedzwa.Fig. 3d), kuratidza kuumbwa kwemonatomic RuNi alloys.Kune sampuli ine RuNi 0.6 wt.% (Fig. 3e), maatomu eRu imwe chete uye zvishoma zvishoma zveRu particles zvakaonekwa paNi NPs, iyo inoratidza kuunganidza kuduku kweRu maatomu nekuda kwekuwedzera kwemutoro.Muchiitiko chemuenzaniso ne 2 wt% RuNi zvinyorwa, akawanda makuru makuru eRu masumbu paNi NPs akawanikwa mumufananidzo weHAADF-STEM (Fig. 3f) uye EDS elemental mapping (Supplementary Fig. 21), zvichiratidza kuunganidza kukuru kweRu. .
mufananidzo weHAADF-STEM, b inofananidzwa neEDS mapping image, c high resolution AC-HAADF-STEM mufananidzo, d yakakurisa STEM mufananidzo uye inowirirana intensity kugoverwa kwe0.4 wt% RuNi sampuli.(e, f) AC–HAADF–STEM mifananidzo yemasampuli ane 0.6 wt.% RuNi uye 2 wt.% RuNi, zvichiteerana.
Kuenzaniswa neNi / Al2O3 uye Ru / Al2O3 samples, DRIFTS spectra yeCO adsorption in situ yakaitwa (Fig. 4a) kuti ienderere mberi nekudzidza zvinyorwa zvemagadzirirwo emasampuli ane 0.4 wt.%, 0.6 wt.% uye 2wt.% RuNi.CO adsorption paRu/Al2O3 sampuli inopa peak huru pa 2060 cm-1 uye imwe yakafara peak pa 1849 cm-1 inonzi ine linear CO adsorption paRu uye kubatanidza pamaatomu maviri eRu akavakidzana, zvichiteerana CO39,40.Kune iyo monometallic Ni sampuli, peak yakasimba inoonekwa chete pa 2057 cm-1, iyo inonzi ine mutsara CO41,42 munharaunda ye nickel.Kune sampuli yeRuNi, kunze kwepamusoro pepamusoro pa 2056 cm-1, pane pfudzi rakasiyana rinotarisa ~ 2030 cm-1.Iyo Gaussian peak fitting method yakashandiswa kugadzirisa zvine musoro kugoverwa kweRuNi samples mu2000-2100 cm-1 range uye kugoverwa kweCO munharaunda yeNi (2056 cm-1) uye Ru (2031-2039 cm) nharaunda.Mapiri maviri epamusoro aive adsorbed mutsara - 1) (Fig. 4b).Sezvineiwo, kubva kuRu/Al2O3 samples (2060 cm–1) kuenda kuRuNi samples (2031-2039 cm–1), iyo yakabatana ine mutsara CO peak mudunhu reRu inopinda yakakosha redshift uye inowedzera nekuwedzera Ru content.Izvi zvinoratidza kuwedzera kwe electronegativity yezvikamu zveRu mumuenzaniso weRuNi, inova mhedzisiro yekutamisa maerekitironi kubva kuNi kuenda kuRu, ichiwedzera d-π electron mhinduro kubva kuRu kuenda kune antibonding CO 2π* orbital.Pamusoro pezvo, kune sampuli ine 0.4 mass% RuNi, hapana bridging adsorption peak yakaonekwa, zvichiratidza kuti maRu particles aripo ari ega maNi atomu (SAA).Panyaya yemasampuli ane 0.6 wt.% RuNi uye 2 wt.% RuNi, kuvapo kwebhiriji CO kunosimbisa kuvapo kweRu multimers kana masumbu, ayo ari muchibvumirano chakanaka nemigumisiro ye AC-HAADF-STEM.
a In situ CO-DRIFTS spectra yeNi/Al2O3, Ru/Al2O3 uye 0.4 wt.%, 0.6 wt.%, 2 wt.% RuNi samples ine helium gas inoyerera mumhando 2100-1500 cm-1 ye20 min.b Scaled uye Gaussian-yakakodzera spectra yeRuNi/Al2O3 sampuro ine yakagadziriswa peak nzvimbo uye FWHM.c In situ Ru K-edge XANES spectra uye d EXAFS Fourier inoshandura spectra yemasampuli akasiyana.K2-inorema wavelet shanduko yeXAFS K-edge Ru masiginecha yakavakirwa paMorlet wavelet ye e Ru samples kubva e Ru foil, f 0.4 wt% RuNi uye g RuO2."au" zvinoreva zvikamu zvisingaite.
Normalized in situ X-ray absorption structure X-ray absorption structure (XANES) spectra yakaitwa kuti idzidze magetsi uye geometric maitiro eRuNi samples neRu foil uye RuO2 samples.Sezvinoratidzwa mufig.4c, sezvo kurodha kweRu kunoderera, kusimba kwemutsara muchena zvishoma nezvishoma kunoderera kubva kuRu/Al2O3 samples kuenda kuRuNi samples.Zvichakadaro, kusimba kwemutsara wakachena we XANES spectrum paK-edge yeNi inoratidza kuwedzera kuduku kubva kuNi sampuli yepakutanga kusvika kumuenzaniso weRuNi (Supplementary Fig. 22).Izvi zvinoratidza shanduko muhuwandu hwema electron uye kurongeka nharaunda yemakomponi eRu.Sezvinoratidzwa mu X-ray photoelectron spectroscopy (XPS) spectra (Supplementary Fig. 23), iyo Ru0 peak yeRuNi sampuli yakashandura kune yakaderera inosunga simba uye iyo Ni0 peak yakashandura kune yakakwirira kusunga simba kana ichienzaniswa ne monometallic Ru uye Ni., iyo inoratidzazve kutamiswa kwemaerekitironi kubva kuNi maatomu kuenda kuRu maatomu muRuNi SAA.The Bader charge analysis of the RuNi SAA(111) surface inoratidza kuti maatomu eRu ari ega anotakura zvakaipa (Ruδ-) anotamiswa kubva pasi peNi atomu (Supplementary Fig. 24), izvo zvinofambirana ne in situ DRIFTS uye XPS zvabuda.Kuti tidzidze yakadzama yekubatanidza chimiro cheRu (Fig. 4d), takaita yakawedzera X-ray absorption yakanaka-grained spectroscopy (EXAFS) muFourier shanduko.Sample ine RuNi 0.4 wt.% ine nhongonya yakapinza pa ~ 2.1 Å, iri munharaunda iri pakati peRu-O (1.5 Å) neRu-Ru (2.4 Å) shells, iyo inogona kunzi inokonzerwa neRu-Ni coordination44, 45. Data fitting results EXAFS (Supplementary Table 5 uye Supplementary Figures 25-28) inoratidza kuti nzira yeRu-Ni ine nhamba yekubatanidza (CN) ye5.4, nepo pasina Ru-Ru uye Ru-O kuwirirana pa 0.4 wt.% RuNi muenzaniso.Izvi zvinosimbisa kuti maatomu makuru eRu akaparadzirwa neatomu uye akakomberedzwa neNi, achigadzira monoatomic alloy.Izvo zvinofanirwa kucherechedzwa kuti iyo peak intensity (~ 2.4 Å) yeRu-Ru kurongeka inoonekwa mumuenzaniso we0.6 wt.% RuNi uye inowedzerwa mumuenzaniso ne2 wt.% RuNi.Kunyanya, EXAFS curve fitting yakaratidza kuti nhamba yeRu-Ru yekubatanidza yakawedzera zvakanyanya kubva ku0 (0.4 wt.% RuNi) kusvika ku2.2 (0.6 wt.% RuNi) uye yakawedzera kusvika ku6.7 (2 wt.% .% RuNi), maererano , zvichiratidza kuti mutoro weRu paunowedzera, maatomu eRu anoungana zvishoma nezvishoma.Iyo K2-inorema wavelet shanduko (WT) yeRu K-edge XAFS masiginecha yakashandiswa zvakare kudzidza nharaunda yekubatanidza yeRu mhando.Sezvinoratidzwa mufig.4e, Ru foil lobes pa 2.3 Å, 9.7 Å-1 inoreva mupiro weRu-Ru.Mumuenzaniso une RuNi 0.4 wt.% (Fig. 4f) hapana lobes pa k = 9.7 Å-1 uye 5.3 Å-1, kunze kwechisungo chepakati cheRu neRu atomu uye O maatomu (Fig. 4g);Ru-Ni inocherechedzwa pa 2.1 Å, 7.1 Å-1, iyo inoratidza kuumbwa kweSAA.Mukuwedzera, iyo EXAFS spectra paK-kumucheto kweNi kune sampuli dzakasiyana-siyana dzakaratidza kusakosha kwakasiyana (Supplementary Fig. 29), zvichiratidza kuti kurongeka kwehutano hweNi hahunyanyi kukanganiswa nepamusoro pemaatomu eRu.Muchidimbu, mhedzisiro ye AC-HAADF-STEM, in situ CO-DRIFTS, uye in situ XAFS kuyedza yakasimbisa kugadzirira kwakabudirira kweRuNi SAA catalysts uye kushanduka kweRu particles paNi NPs kubva kuatomu imwe kuenda kuRu multimers nekuwedzera Ru load.Mukuwedzera, iyo HAADF-STEM mifananidzo (Supplementary Fig. 30) uye EXAFS spectra (Supplementary Fig. 31) yeRuNi SAA catalysts yakashandiswa yakaratidza kuti kupararira kwenyika uye kurongeka kwemaitiro eRu maatomu haana kuchinja zvakanyanya mushure me5, zvichiratidza. kuti iyo yakagadzikana RuNi SAA catalyst .
H2-TPD zviyero zvakaitwa kuti zvidzidze dissociative adsorption ye hydrogen pane zvakasiyana-siyana zvinokonzera uye zvigumisiro zvakaratidza kuti zvose izvi zvinogadzirisa zvine simba rakasimba reH2 dissociation ne desorption peak pa ~ 100 ° C (Supplementary Fig. 32).Migumisiro yehuwandu hwekuongorora (Supplementary Fig. 33) haina kuratidza mutsara wakajeka kuwirirana pakati pekugadzirisa uye kuwanda kwehydrogen desorption.Mukuwedzera, takaita zviedzo neD2 isotopes uye takawana kinetic isotope effect (KIE) kukosha kwe1.31 (TOFH / TOFD) (Supplementary Fig. 34), zvichiratidza kuti kushandiswa uye kuparadzaniswa kweH2 kwakakosha asi kwete chiyero-kuderedza matanho.DFT macalculations akaitwa kuti awedzere kuongorora adsorption uye dissociation maitiro ehydrogen paRuNi SAA versus metallic Ni chete (Supplementary Fig. 35).Kumasamples eRuNi SAA, H2 mamorekuru anonyanya kuda chemisorb pane imwechete Ru maatomu ane adsorption simba re -0.76 eV.Zvadaro, haidrojeni inoparadzaniswa kuita maatomu maviri anoshanda panzvimbo yeRu-Ni RuNi SAA, ichikunda chipingamupinyi chesimba che0.02 eV.Pamusoro penzvimbo dzeRu, ma molecules eH2 anogonawo kuiswa chemisorbed panzvimbo dzepamusoro dzeNi atomu dziri padyo neRu (adsorption energy: -0.38 eV) obva apatsanurwa kuita maH maviri panzvimbo dzeRu-Ni neNi-Ni.Atomic chipingamupinyi 0.06 eV.Kusiyana neizvi, zvipingamupinyi zvesimba zvekushambadza uye kuparadzaniswa kwemamorekuru eH2 paNi (111) pamusoro -0.40 eV uye 0.09 eV, zvichiteerana.Iyo yakanyanya kuderera simba chipingamupinyi uye misiyano isingakoshi inoratidza kuti H2 inoparadzaniswa zviri nyore pamusoro peNi uye RuNi surfactants (Ni-saiti kana Ru-saiti), iyo isiri iyo yakakosha inokanganisa basa rayo rinokurudzira.
Activated adsorption yemamwe mapoka anoshanda akakosha pakusarudza hydrogenation ye substrates.Nokudaro, takaita DFT calculations kuti tiongorore zvinogona kugadziriswa zve 4-NS adsorption uye nzvimbo dzinoshanda paRuNi SAA (111) pamusoro, uye zvigumisiro zvekugadzirisa zvinoratidzwa muSupplementary Fig. 36. Inoratidzika seyakafanana configuration (Fig. 5a uye Supplementary Fig. 36e), umo maatomu eN anowanikwa munzvimbo dzeRu-Ni uye maatomu maviri eO akasungirirwa kuRu-Ni interface inoratidza yakaderera adsorption energy level (-3.14 eV).Izvi zvinoratidzira iyo thermodynamically yakanakira adsorption regime kana ichienzaniswa yakatwasuka uye mamwe magadzirirwo akafanana (Supplementary Fig. 36a-d).Mukuwedzera, mushure mekudsorption ye4-HC paRuNi SAA (111), kureba kweN-O1 (L (N-O1)) chisungo muboka re nitro yakawedzera kusvika ku1.330 Å (Fig. 5a), iyo yakawanda. kureba kupfuura kureba kwegasi 4- NS (1.244 Å) (Supplementary Fig. 37), kunyange kudarika L (N-O1) (1.315 Å) paNi (111).Izvi zvinoratidza kuti iyo activated adsorption yeN-O1 zvisungo pamusoro peRuNi PAA inowedzerwa zvakanyanya kana ichienzaniswa neyekutanga Ni(111).
a Adsorption zvigadziriso zve4-HC paNi(111) uye RuNi SAA(111) (Eads) nzvimbo (parutivi nepamusoro maonero).Ru - violet, Ni - girini, C - orenji, O - tsvuku, N - bhuruu, H - chena.b In situ FT-IR spectra ye gaseous uye chemisorbed 4-HC pane monometallic surfactants Ni, Ru, RuNi (0.4 wt. %) uye 2 wt.% RuNi, zvichiteerana.c Normalized in situ XANES and d-phase-corrected Fourier EXAFS at the Ru K-edge of 0.4 wt % RuNi PAA during 4-NS adsorption (RuNi SAA–4NS) and hydrogenation steps (RuNi SAA–4NS–H2) .Shanduro spectra ;...e Projection density of states (PDOS) yenzvimbo yekutanga yeRuNi SAA(111), N-O1 mune gaseous 4-NS uye adsorbed 4-NS paRuNi SAA(111)."au" zvinoreva zvikamu zvisingaite.
Kuti uwedzere kuedza maitiro ekushambadza kwe4-NS, in situ FT-IR zviyero zvakaitwa paNi monometallic, Ru monometallic, 0.4 wt% RuNi (SAA), uye 2 wt% RuNi catalysts (Fig. 5b).Iyo FT-IR spectrum ye gaseous 4-NS yakaratidza matatu emhando yepamusoro pa1603, 1528, uye 1356 cm-1, iyo yakapihwa ν(C=C), νas(NO2), uye νs(NO2)46,47, 48.Pamberi pe monometallic Ni, ma redshifts emabhendi ese matatu anoonekwa: v(C=C) (1595 cm–1), νas(NO2) (1520 cm–1), uye νs(NO2) (1351 cm–1) ., iyo inoratidza chemisorption yeC = C uye -NO2 mapoka ari pamusoro peNi (zvichida, mukugadzirisa kweparallel adsorption).Kune sampuli ye monometallic Ru, ma redshifts emabhandi matatu aya (1591, 1514, uye 1348 cm-1, zvichiteerana) zvine chekuita ne monometallic Ni zvakawanikwa, izvo zvinoratidza kuwedzeredzwa zvishoma kwemapoka e nitro uye С=С zvisungo paRu.Muchiitiko che 0.4 wt.% RuNi (SAA), iyo ν(C=C) bhendi iri pakati pe1596 cm–1, iri padyo nemonometallic Ni band (1595 cm–1), zvichiratidza kuti mapoka evinyl anowanzo kudsorb Ni paRuNi. SAA nzvimbo.Pamusoro pezvo, mukupesana neiyo monometallic catalyst, kusimba kweiyo νs(NO2) bhendi (1347 cm-1) haina kusimba kupfuura iyo νas(NO2) bhendi (1512 cm-1) pa0.4 wt.% RuNi (SAA) )Chiitiko chakafanana chakaonekwawo mumuenzaniso neRuNi zvinyorwa zve 2 wt.%.Migumisiro iri pamusoro apa inosimbisa kuti synergistic effect ye bimetallic centers muPAA RuNi inokurudzira polarization uye kupatsanurwa kwemapoka e nitro, izvo zviri muchibvumirano chakanaka ne optimal adsorption configuration inowanikwa neDFT calculations.
In situ XAFS spectroscopy yakaitwa kuti idzidze kushanduka kwesimba remagetsi chimiro uye coordination mamiriro eRuNi SAA panguva ye4-NS adsorption uye catalytic reaction.Sezvo zvinogona kuonekwa kubva kuK-edge XANES spectrum yeRu (Fig. 5c), mushure mekushambadza kwe4-HC, 0.4 wt.% RuNi PAA, mupendero wekunyura unoshandiswa zvakanyanya kumasimba akakwirira, ayo anoperekedzwa nekuwedzera kwesimba remutsetse muchena, izvo zvinoratidza kuti Ru marudzi Partial oxidation inoitika nekuda kwekuchinjisa maerekitironi kubva kuRu kuenda ku4-NS.Mukuwedzera, iyo Phase-yakagadziriswa Fourier inoshandura EXAFS spectrum ye adsorbed 4-NS RuNi SAA (Fig. 5d) inoratidza kuwedzera kwakajeka kwezviratidzo pa ~ 1.7 Å uye ~ 3.2 Å, iyo inobatanidza nekuumbwa kweRu-O coordination.Iyo XANES uye EXAFS spectra ye 0.4 wt% RuNi SAA yakadzokera kumamiriro avo ekutanga mushure mekujoinwa kwemaminetsi makumi matatu ehydrogen gasi.Izvi zviitiko zvinoratidza kuti mapoka e nitro adsorbed panzvimbo dzeRu kuburikidza neRu-O zvisungo zvinoenderana nekubatana kwemagetsi.Kana iri XAFS spectra yeNi-K edge in situ (Supplementary Fig. 38), hapana shanduko dziri pachena dzakaonekwa, izvo zvingave zvichikonzerwa nekuita kwekuderedzwa kweNi atomu muchikamu chikuru pamusoro peNi particles.The akafanotaurwa density yematunhu (PDOS) of RuNi SAA (Fig. 5e) inoratidza kuti isingagarwi mamiriro nitro boka pamusoro Femi level rinowedzera uye kufamba pazasi Femi level ari adsorbed state, izvo zvakare zvinoratidza kuti maerekitironi kubva d- mamiriro eRuNi SAA shanduko kuenda kunzvimbo isina munhu mu −NO2.The charge density difference (Supplementary Fig. 39) uye Bader charge analysis (Supplementary Fig. 40) inoratidza kuti integrated electron density ye4-NS inounganidza mushure mekudsorption kwayo pamusoro peRuNi SAA (111).Mukuwedzera, iyo -NO2 charge density yakawedzera zvakanyanya kana ichienzaniswa neboka revinyl mu4-NS nekuda kwekutumira maerekitironi paRu-Ni interface, zvichiratidza kushandiswa kwakananga kweNO bond muboka renitro.
In situ FT-IR yakaitwa kuti itarise iyo catalytic process ye4-NS hydrogenation reaction pane catalyst samples (Fig. 6).Nokuda kwekutanga nickel catalyst (Fig. 6a), zvishoma zvishoma kuderera kwehuwandu hwe nitro (1520 uye 1351 cm-1) uye C = C (1595 cm-1) mabhendi akaonekwa paaipfuura H2 ye12 min, iyo. inoratidza kuti − Activation NO2 uye C=C hazvina kusimba.Pamberi pe monometallic Ru (Fig. 6b), iyo ν(C=C) bhendi (pa 1591 cm–1) inokurumidza kutetena mukati me 0–12 min, ukuwo νs(NO2) uye νas(NO2) mabhendi akaderedzwa zvakanyanya. .Zvishoma Izvi zvinoratidza kushandiswa kwekuda kweboka revinyl rehydrogenation, zvichiita kuti paumbwe 4-nitroethylbenzene (4-NE).Muchiitiko che 0.4 wt.% RuNi (SAA) (Fig. 6c), the νs(NO2) band (1347 cm–1) inokurumidza kupera nekuwanda kwehydrogen, ichiperekedzwa nekuora zvishoma nezvishoma kwe ν(N=O );bhendi nyowani yakatarisana ne1629 cm-1 yakaonekwa zvakare, yakakonzerwa nekukotama vibrations yeNH.Mukuwedzera, iyo bhendi ye ν(C = C) (1596 cm-1) inongoratidza kuderera kushoma mushure megumi nemaviri min.Iyi shanduko ine simba inosimbisa polarization uye hydrogenation ye -NO2 kusvika -NH2 ne 0.4 wt% RuNi (SAA) inobva pane yakasarudzika chemoselectivity yakananga ku4-aminostyrene.Yemuenzaniso we2 wt.% RuNi (Fig. 6d), kuwedzera pakuonekwa kwebhendi idzva pa1628 cm–1 inonzi δ(NH), ν(C=C) bhendi rinonyanya kuderera uye rinonyangarika nekuwedzera bhendi reboka renitro (1514). uye 1348cm–1).Izvi zvinoratidza kuti C = C uye -NO2 inoshandiswa zvinobudirira nekuda kwekuvapo kweRu-Ru uye Ru-Ni interfacial centers, maererano, iyo inopindirana nekuumbwa kwe4-NE uye 4-AE pa2 wt.% RuNi catalyst.
In situ FT-IR spectra ye4-NS hydrogenation pamberi pe monometallic Ni, b monometallic Ru, c 0.4 wt% RuNi SAA, uye d 2 wt% RuNi muH2 inoyerera pa1700-1240 cm- Range 1 yakanyorwa se kuita gasi mushure me0, 3, 6, 9 uye 12 maminetsi, zvichiteerana."au" zvinoreva zvikamu zvisingaite.Inogona kugovera simba uye inowirirana optimized zvimiro zveC=C hydrogenation uye HAPANA scission kupinda 4-NS pa e Ni(111) uye f RuNi SAA(111) pamusoro.Ru - violet, Ni - girini, C - orenji, O - tsvuku, N - bhuruu, H - chena.“ads”, “IS”, “TS”, uye “FS” inomiririra adsorption state, yekutanga mamiriro, shanduko, uye yekupedzisira mamiriro, zvichiteerana.
Nzira dzinogona kuitika dze4-NS shanduko kuenda kuNi(111) uye RuNi SAA(111), kusanganisira C=C hydrogenation uye NO bond cleavage, yakaongororwa nekuverenga kweDFT kuti iwedzere kujekesa basa rakakosha re4-NS.Zvikamu zveRu-Ni interface yekugadzirwa kwe4-AS zvinangwa.Pamusoro peNi (111) pamusoro (Fig. 6e), zvipingamupinyi zvesimba zveNO scission uye hydrogenation yemapoka evinyl muchikamu chekutanga ndeye 0.74 uye 0.72 eV, zvichiteerana, izvo zvinoratidza kuti chemoselective hydrogenation yemapoka e nitro mu4-HC ndiyo. zvisina kunaka.ye monometallic nickel nzvimbo.Pane zvinopesana, simba rekudzivirira kweNO dissociation chete 0.46 eV yakakwirira kupfuura yeRuNi SAA (111), iyo yakaderera zvikuru kupfuura yeC = C bond hydrogenation (0.76 eV) (Fig. 6f).Izvi zvinosimbisa pachena kuti Ru-Ni interfacial centers inonyatso kudzikisa simba rekudzivirira kweNO scission mumapoka e-nitro, zvichiita kuti kuderedzwa kwemafuta e nitro kuenzaniswa nemapoka eC = C paRuNi surfactant surface, iyo inobvumirana nemigumisiro yekuedza.
Maitiro ekugadzirisa uye akaverengerwa simba curves ye4-NS hydrogenation paRuNi SAA yakaongororwa zvichienderana neDFT calculations (Fig. 7), uye yakadzama adsorption configuration yematanho makuru inoratidzwa muSupplementary Fig. 41. Kugadzirisa purogiramu yekuverenga, zvipingamupinyi zvinogadzira simba zvemamorekuru emvura zvakabviswa kubva pakuverenga.ndiro mienzaniso9,17.Sezvinoratidzwa mufig.7, iyo 4-NS mamorekuru anotanga kunyudzwa mukuwirirana paRuNi surfactant, uye maatomu maviri eO ari muboka renitro anosungwa kuRu-Ni interfacial centers (S0; danho I).Zvadaro, iyo NO bond yakasungirirwa panzvimbo yeRu yakaputsika, iyo inofambidzana nekuumbwa kwe nitroso yepakati (C8H7NO *) panzvimbo yeRu-Ni interface uye O * panzvimbo isina chinhu yeNi (S0 → S1 kuburikidza neTS1; simba chipingamupinyi: 0.46 eV, danho rechipiri).O* radicals anoiswa hydrogenated neanoshanda H maatomu kuti aumbe H2O mamorekuru ane exotherm ye0.99 eV (S1 → S2).Zvipingamupinyi zvemagetsi zveku hydrogenation yeC8H7NO* yepakati (Supplementary Figures 42 ne43) inoratidza kuti maatomu eH anoitika kubva munzvimbo dzisina nzvimbo dzeRu-Ni anonyanya kurwisa maatomu eO kupfuura maatomu eN, zvichikonzera C8H7NOH* (S2 → S4; simba rinodzivirira TS2: 0.84) eV, danho III).Maatomu eN ari muC8H7NOH* akabva aitwa hydrogen kuti aite C8H7NHOH* mushure mekuyambuka 1.03 eV barrier (S4→S6; danho IV), rinova danho rinotsanangura rekuita kwese.Zvadaro, chisungo cheN-OH muC8H7NHOH* chakatyorwa paRu-Ni interface (S6 → S7; simba rinovharira: 0.59 eV; nhanho V), mushure mezvo OH* yakaitwa hydrogenated kuHO (S7 → S8; exotherm: 0.31 eV ) Mushure maizvozvo, maatomu eN enzvimbo dzeRu-Ni hollow muC8H7NH* akaiswawo hydrogenated kuti aite C8H7NH2* (4-AS) ine simba rinovharira 0.69 eV (S8 → S10; danho VI).Pakupedzisira, 4-AS uye HO mamorekuru akacheneswa kubva kuRuNi-PAA pamusoro, uye iyo catalyst yakadzokera kune yayo yekutanga (danho VII).Ichi chakasarudzika chimiro chepakati pakati peimwe Ru maatomu neNi substrates, inoperekedzwa neiyo synergistic mhedzisiro yehost doping muRuNi SAA, inoguma muchiitiko chakatanhamara uye chemoselectivity ye4-NS hydrogenation.
Mupunga.4. Schematic diagram yemuchina we hydrogenation reaction yeNS kusvika 4-AS paRuNi PAA pamusoro.Ru - violet, Ni - girini, C - orenji, O - tsvuku, N - bhuruu, H - chena.Iyo inset inoratidza kugoverwa kwesimba rinogona kuitika re4-NS hydrogenation paRuNi SAA (111) pamusoro, inoverengwa pahwaro hweDFT."S0" inomiririra nyika yekutanga, uye "S1-S10" inomiririra nhevedzano yematunhu adsorption.“TS” inomirira shanduko.Nhamba dziri mumabhuraketi dzinomiririra zvipingamupinyi zvesimba zvematanho makuru, uye nhamba dzakasara dzinomiririra simba rekushambadza repakati rinoenderana.
Nokudaro, RuNi SAA catalysts yakawanikwa uchishandisa electrosubstitution reactions pakati peRuCl3 neNi NPs yakawanikwa kubva kune LDH precursors.Kuenzaniswa neyakambotaurwa monometallic Ru, Ni uye zvimwe heterogeneous catalysts, iyo yakaguma RuNi SAA yakaratidza hukuru hwekuita hwekuita kwe4-NS chemoselective hydrogenation (4-AS goho:> 99%; TOF kukosha: 4293 h-1).Iwo akasanganiswa maitiro anosanganisira AC-HAADF-STEM, in situ CO-DRIFTS, uye XAFS yakasimbisa kuti maatomu eRu akange asingafambire paNi NPs padanho reatomu rimwe chete kuburikidza neRu-Ni mabhondi, ayo aiperekedzwa nekufambiswa kweelectron kubva kuNi kuenda kuRu.In situ XAFS, FT-IR miedzo, uye DFT kuverenga kwakaratidza kuti Ru-Ni interface site inoshanda senzvimbo yemukati inoshandiswa kuitira kushandiswa kwekuda kweNO bond muboka re nitro;synergism pakati peRu nevavakidzani Ni masayiti inofambisa yepakati activation uye hydrogenation, nekudaro inovandudza hunyanzvi hwekuita.Iri basa rinopa nzwisiso muhukama pakati peaviri-anoshanda masaiti uye inokonzeresa maitiro eSAA padanho reatomu, ichigadzira nzira yekugadzira zvine musoro kwemamwe maviri-nzira anokonzeresa ane anodikamwa kusarudza.
Iwo analytical reagents akashandiswa mukuyedza akatengwa kubva kuSigma Aldrich: Al2(SO4)3 18H2O, sodium tartrate, CO (NH2)2, NH4NO3, Ni(NO3)2 6H2O, RuCl3, ethanol, 4-nitrostyrene (4- NS) , 4-aminostyrene, 4-nitroethylbenzene, 4-aminoethylbenzene uye nitrostyrene.Mvura yakacheneswa yakashandiswa mukuedzwa kwese.
Hierarchical NiAl LDHs akagadzirwa seanotangira ne in situ kukura.Kutanga, urea (3.36 g), Al2 (SO4) 3 · 18H2O (9.33 g) uye sodium tartrate (0.32 g) yakanyungudutswa mumvura yakasvibiswa (140 ml).Mhinduro yakagadziriswa yakaendeswa kune Teflon-coated autoclave uye inopisa kusvika 170 ° C kwe3 h.Mhepo yakakonzerwa yakashambidzwa nemvura yakasvibiswa uye yakanyatsoomeswa, mushure meiyo yakaverengerwa pa500 ° C (2 ° C min-1; 4 h) kuwana amorphous Al2O3.Zvadaro Al2O3 (0.2 g), Ni(NO3)2 6H2O (5.8 g) uye NH4NO3 (9.6 g) yakaparadzirwa mumvura yakanatswa (200 ml) uye pH yakagadziriswa kusvika ~ 6.5 nekuwedzera 1 mol l -1 ammonia mvura..Kumiswa kwakaendeswa muflask uye kwakachengetwa pa90 ° C kwe48 h kuwana NiAl-LDH.Zvadaro NiAl-LDH poda (0.3 g) yakaderedzwa murukova rweH2/N2 (10/90, v/v; 35 ml min–1) pa500°C kwe4 h (kupisa mwero: 2°C min -1 )Kugadzirira kwemasampuli e monometallic nickel (Ni/Al2O3) yakaiswa pane amorphous Al2O3.Iwo akaiswa bimetallic samples eRuNi akagadzirwa nenzira ye electrodisplacement.Kazhinji, sampuli itsva yeNi/Al2O3 (0.2 g) yakaparadzirwa mu30 ml yemvura yakachena, ipapo mhinduro yeRuCl3 (0.07 mmol l-1) yakawedzerwa zvishoma nezvishoma uye yakamutswa zvakasimba kwemaminitsi makumi matanhatu pasi pekuchengetedzwa kweN2 atmosphere. .Mhedzisiro yakakonzerwa yakasvibiswa, yakashambidzwa nemvura yakachena, uye yakaomeswa muvheni yevacuum pa50 ° C ye24 h, ichiwana sampuli ine 0.1% RuNi.Pamberi pekuongorora kwecatalytic, masampuli achangobva kugadzirwa akatanga kuderedzwa muH2/N2 kuyerera (10/90, v/v) pa300 ° C (kupisa mwero: 2 ° C min-1) kwe1 h, uyezve kupisa mukati. N2 Kutonhorera kusvika kukamuri tembiricha.Zvekureva: samples ine Ru/Al2O3 zvirimo zve 0.4% uye 2% nehukuru, ine chaiyo Ru zvirimo zve 0.36% nehukuru uye 2.3% nehukuru, zvakagadzirirwa nekunaya kwemvura nekunaya uye kupisa pa300 ° C (kushandiswa kweH2/ N2 : 10/90, v/v, mwero wekupisa: 2 °C min–1) kwemaawa matatu.
X-ray diffraction (XRD) miedzo yakaitwa paBruker DAVINCI D8 ADVANCE diffractometer ine Cu Kα radiation source (40 kV uye 40 mA).A Shimadzu ICPS-7500 Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) yakashandiswa kuona kuwanda chaiko kwezvinhu mumasampuli akasiyana.Scanning electron microscopy (SEM) mifananidzo yakafananidzirwa uchishandisa Zeiss Supra 55 electron maikorosikopu.N2 adsorption-desorption miedzo yakaitwa paMicromeritics ASAP 2020 mudziyo uye chaiyo nzvimbo yakaverengerwa uchishandisa iyo Brunauer-Emmett-Teller (BET) nzira yakawanda.Transmission electron microscopy (TEM) maitiro akaitwa paJEOL JEM-2010 high-resolution transmission electron maikorosikopu.Yakakwira Angle Aberration Yakagadziriswa Scanning Transmission Electron Microscope Rima Field (AC-HAADF) - STEM ine FEI Titan Cube Themis G2 300 ine spherical aberration corrector uye Energy Dispersive X-ray Spectroscopy (EDS) system uye JEOL JEM-ARM200F zviyero) uye EDS mamepu .Yakanaka chimiro X-ray absorption spectroscopy (XAFS) in situ K-edge yeRu uye Ni K-edge yakayerwa pamatanho 1W1B uye 1W2B eBeijing Synchrotron Radiation Facility (BSRF) yeInstitute of High Energy Physics (IHEP), China. .Academy yeSainzi (KAN).Pulsed CO chemisorption uye tembiricha-programmed hydrogen desorption (H2-TPD) kuedza kwakaitwa paMicromeritics Autochem II 2920 chiridzwa uchishandisa thermal conductivity detector (TCD).Iyo in situ DRIFTS uye FT-IR zviedzo zvakaitwa paBruker TENSOR II infrared spectrometer ine yakagadziridzwa in situ reaction cell uye inocherekedza MCT detector.Details characterization nzira dzinotsanangurwa muSupplementary Information.
Kutanga, iyo substrate (4-NS, 1 mmol), solvent (ethanol, 8 ml) uye catalyst (0.02 g) zvakanyatsowedzerwa kune 25 ml stainless steel autoclave.Iyo reactor yakabva yacheneswa zvachose ne 2.0 MPa (> 99.999%) hydrogen 5 nguva, uye yakazomanikidzwa uye yakavharwa ku 1.0 MPa neH2.Mhedzisiro yacho yakaitwa pa60 ° C pane imwe nguva inokonzera 700 rpm.Mushure mekuita, zvigadzirwa zvakaguma zvakaonekwa neGC-MS uye kuongororwa kwehuwandu uchishandisa Shimadzu GC-2014C gasi chromatography system ine GSBP-INOWAX capillary column (30 m×0.25 mm × 0.25 mm) uye FID detector.Iyo 4-nitrostyrene shanduko uye kusarudza kwechigadzirwa kwakatemwa sezvinotevera:
Turnover frequency (TOF) maitiro akaverengerwa se mol 4-NS yakashandurwa pane mol simbi nzvimbo paawa (mol4-NS mol-1 h-1) zvichibva pane yakaderera 4-NS shanduko (~ 15%).Kana iri nhamba yeRu node, Ru-Ni interface nodes uye huwandu hwese hwepamusoro maatomu esimbi.Payedzo yekudzokorodza zvakare, iyo catalyst yakaunganidzwa ne centrifugation mushure mekuita, yakagezwa katatu ne ethanol, uyezve yakaunzwa mu autoclave kune inotevera catalytic cycle.
Yese density functional theory (DFT) kuverenga kwakaitwa uchishandisa Vienna ab initio simulation package (VASP 5.4.1).Iyo Generalized Gradient Approximation (GGA) PBE basa rinoshandiswa kutsanangura maelectronic exchange uye kuwirirana mamiriro.Iyo Projector Augmented Wave (PAW) nzira inoshandiswa kutsanangura kudyidzana kuri pakati peatomu nuclei nemaerekitironi.Iyo Grimm DFT-D3 nzira inotsanangura maitiro evan der Waals kupindirana pakati pe substrate uye interface.Kuverengera kweMagetsi Zvipingamupinyi nekukwira Elastic Mabhendi ane Image Boost (CI-NEB) uye Dimer Methods.Kuongororwa kwakawanda kweiyo oscillations kwakaitwa, zvichisimbisa kuvepo kweiyo imwe chete yekufungidzira frequency mune imwe neimwe shanduko mamiriro (Supplementary Figures 44-51).Mamwe maverengero akadzama anotsanangurwa mune yekuwedzera ruzivo.
Iyo data huru inotsigira zvirongwa mune ino chinyorwa inopiwa mune iyo source data mafaira.Mamwe data anoenderana nechidzidzo ichi anowanikwa kubva kune vakasiyana vanyori kana paine chikumbiro chine musoro.Ichi chinyorwa chinopa data rekutanga.
Korma A. uye Serna P. Chemoselective hydrogenation ye nitro makomisheni ane anotsigirwa egoridhe catalysts.Sayenzi 313, 332–334 (2006).
Formenti D., Ferretti F., Sharnagle FK uye Beller M. Kuderedzwa kwe nitro compounds uchishandisa 3d base metal catalysts.Chemical.119, 2611–2680 (2019).
Tan, Y. et al.Au25 nanoclusters inotsigirwa paZnAl hydrotalcite se precatalysts ye chemoselective hydrogenation ye 3-nitrostyrene.Angie.Chemical.mukati Ed.56, 1–6 (2017).
Zhang L, Zhou M, Wang A, uye Zhang T. Selective hydrogenation pane zvinotsigirwa nesimbi catalysts: kubva nanoparticles kusvika kune rimwe nerimwe maatomu.Chemical.120, 683–733 (2020).
Zuva, K. et al.Monoatomic rhodium catalysts yakavharidzirwa mu zeolite: Inoshanda hydrogen kugadzirwa uye inosarudza cascade hydrogenation ye nitroaromatic makomisheni.Angie.Chemical.mukati Ed.58. 18570–18576 (2019).
Tian, ​​S.et al.Diatomic Pt heterogeneous catalyst ine yakanakisa catalytic kuita kwekusarudza hydrogenation uye epoxidation.National commune.12, 3181 (2021).
Wang, Yu.et al.Chemoselective hydrogenation ye nitroarenes pane nanosized iron (III) -OH-platinum interfaces.Angie.Chemical.mukati Ed.59, 12736–12740 (2020).
Wei, H. et al.FeOx yakatsigira platinum monatomic uye pseudomonoatomic catalysts ye chemoselective hydrogenation ye functionalized nitroaromatic compounds.National commune.5, 5634 (2014).
Khan, A. et al.Kupatsanurwa kwemaatomu ePt anotevedzana uye kuumbwa kwePt-Zn intermetallic nanoparticles kuti iite kusarudzwa kwe4-nitrophenylacetylene hydrogenation.National commune.10, 3787 (2019).
Wang, K. nevamwe.Kutarisa kusingaenzaniswi saizi kutsamira kwemonatomic Pt catalysts inotsigirwa paCeO2.Chemistry 6, 752–765 (2020).
Feng Yu et al.Pane-inoda ultra-selective hydrogenation system uchishandisa yakatsetseka Pd-Cd nanocubes.Jam.Chemical.nzanga.142, 962–972 (2020).
Fu, J. nevamwe.Synergistic mhedzisiro yekusimudzira catalysis mune mbiri monatomic catalysts.Catalan SAU.11, 1952–1961 (2021).
Liu, L. nevamwe.Kuona kushanduka kwemaatomu esimbi imwe chete uye nanoclusters pasi pemamiriro ekuita: ndeapi ari kushanda nzvimbo dzecatalytic?Catalan SAU.9, 10626–10639 (2019).
Yang, N. et al.Amorphous/crystalline heterogeneous palladium nanosheets: imwe-poto synthesis uye yakanyanya kusarudza hydrogenation reaction.Advanced alma mater.30, 1803234 (2018).
Gao, R. et al.Kuputsa kutengeserana pakati pekusarudza uye chiitiko chenickel-based hydrogenation catalysts nekugadzirisa steric mhedzisiro uye d-bhendi nzvimbo.Sayenzi yepamusoro.6, 1900054 (2019).
Lee, M. nevamwe.Active sosi yeCo-NC catalysts ye chemoselective hydrogenation ye nitroaromatic compounds.Catalan SAU.11, 3026–3039 (2021).