The activation and reduction of N_(2)to produce ammonia under mild conditions is of great interest,but challenges remain.Here,we report a breakthrough in efficient dinitrogen cleavage by employing small Ptn+(n=1–4)cl...The activation and reduction of N_(2)to produce ammonia under mild conditions is of great interest,but challenges remain.Here,we report a breakthrough in efficient dinitrogen cleavage by employing small Ptn+(n=1–4)clusters and convenient plasma assistance.The reactivity of Pt3+is found to be substantially higher than that of other clusters,and the formed Pt3N7+shows prominent mass abundance among the odd-nitrogen products.We illustrate that a chain reaction path within dual cluster cooperation,especially via a“3+2”mode,is beneficial to N≡N triple bond dissociation,embodying efficient synergistic catalysis.A key intermediate containing a bridged N_(2)of binding with two Pt clusters facilitates N_(2)activation with significantly enhanced interactions between the d orbitals of Pt and the antibondingπ*-orbitals of N_(2).Furthermore,by reacting the Pt_(n)N_(m)+clusters with H_(2),we observed hydrogenation products of both evenand odd-hydrogen species,indicative of ammonia release.The in situ synthesized platinum nitride clusters,typically Pt_(3)N_(7)+,induce a highly active N site for hydrogen anchoring,enabling a cost-effective hydrotreating process for ammonia synthesis.展开更多
Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate.Compared to the enantiomeric excess(e.e....Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate.Compared to the enantiomeric excess(e.e.)value(71.4%) obtained without the presence of metal cations,obvious e.e.enhancement(up to 82.5%)was resulted from the addition of Zn^(2+) but with a certain decrease in activity.The reaction parameters in the presence of Zn^(2+) were also studied.It was found that the Pt colloidal catalysts in the presence of metal cations performed very differently from that in the absence of metal cations.展开更多
The modification of some metal complexes on Pt/Al2O3 clusters leads to remarkable increases in both the activity and the selectivity for meso-2,3-butanediol in the stereoselectivity hydrogenation of 2,3-butanedione.
Regioselective hydrogenation of 2,3 pentanedione was investigated over poly ( N vinyl 2 pyrrolidone) stabilized platinum nanoclusters (PVP Pt) with metal cation as modifier. The results indicated that the addition of ...Regioselective hydrogenation of 2,3 pentanedione was investigated over poly ( N vinyl 2 pyrrolidone) stabilized platinum nanoclusters (PVP Pt) with metal cation as modifier. The results indicated that the addition of metal cations as well as the increase of solvent polarity could enhance the regioselectivity for 3 hydroxy 2 pentanone. The use of Sn 2+ could remarkably activate the hydrogenation reaction while the use of Ce 3+ decreased the reaction activity greatly. The modification effect was explained by the toxic effect of metal cations on the metal catalyst, the polarization effect of metal cations on the carbonyl group and the steric effect of the substrate itself.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(grant nos.21802146 and 21722308)the CAS Key Research Project of Frontier Science(CAS grant no.QYZDB-SSW-SLH024)the Frontier Cross Project of national laboratory for molecular sciences(grant no.051Z011BZ3).
文摘The activation and reduction of N_(2)to produce ammonia under mild conditions is of great interest,but challenges remain.Here,we report a breakthrough in efficient dinitrogen cleavage by employing small Ptn+(n=1–4)clusters and convenient plasma assistance.The reactivity of Pt3+is found to be substantially higher than that of other clusters,and the formed Pt3N7+shows prominent mass abundance among the odd-nitrogen products.We illustrate that a chain reaction path within dual cluster cooperation,especially via a“3+2”mode,is beneficial to N≡N triple bond dissociation,embodying efficient synergistic catalysis.A key intermediate containing a bridged N_(2)of binding with two Pt clusters facilitates N_(2)activation with significantly enhanced interactions between the d orbitals of Pt and the antibondingπ*-orbitals of N_(2).Furthermore,by reacting the Pt_(n)N_(m)+clusters with H_(2),we observed hydrogenation products of both evenand odd-hydrogen species,indicative of ammonia release.The in situ synthesized platinum nitride clusters,typically Pt_(3)N_(7)+,induce a highly active N site for hydrogen anchoring,enabling a cost-effective hydrotreating process for ammonia synthesis.
基金The project is partially supported by the Natural Science Foundation of Hubei Province Contract(No.2003ABA072)
文摘Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate.Compared to the enantiomeric excess(e.e.)value(71.4%) obtained without the presence of metal cations,obvious e.e.enhancement(up to 82.5%)was resulted from the addition of Zn^(2+) but with a certain decrease in activity.The reaction parameters in the presence of Zn^(2+) were also studied.It was found that the Pt colloidal catalysts in the presence of metal cations performed very differently from that in the absence of metal cations.
文摘The modification of some metal complexes on Pt/Al2O3 clusters leads to remarkable increases in both the activity and the selectivity for meso-2,3-butanediol in the stereoselectivity hydrogenation of 2,3-butanedione.
文摘Regioselective hydrogenation of 2,3 pentanedione was investigated over poly ( N vinyl 2 pyrrolidone) stabilized platinum nanoclusters (PVP Pt) with metal cation as modifier. The results indicated that the addition of metal cations as well as the increase of solvent polarity could enhance the regioselectivity for 3 hydroxy 2 pentanone. The use of Sn 2+ could remarkably activate the hydrogenation reaction while the use of Ce 3+ decreased the reaction activity greatly. The modification effect was explained by the toxic effect of metal cations on the metal catalyst, the polarization effect of metal cations on the carbonyl group and the steric effect of the substrate itself.
基金National Natural Science Foundation of China(21665019,21165011)Natural Science Foundation of the Inner Mongolia Autonomous Region(2015MS0215)+2 种基金The Fundamental Research Funds for the Central Universities(2018JBZ107,2018RC022,2017JBM068,S18I00010,S17I00010,S16C00010)The “1000 Youth Talents plan” ProjectThe “Excellent One Hundred” Project of Beijing Jiaotong University
基金supported by the National Natural Science Foundation of China(21576251,21676269,21808212,21878283)the Youth Innovation Promotion Association CAS(2017223)+5 种基金the “Strategic Priority Research Program” of the Chinese Academy of Sciences(XDB17020100)National Key Projects for Fundamental Research and Development of China(2016YFA0202801)China Postdoctoral Science Foundation(2019M652578)the Postdoctoral Sponsorship in Henan Province(1902015)Science and Technology Program of Henan Province(192102210034)Zhongyuan Postdoctoral Program for Innovation Talents~~
