Our recent theoretical studies have screened out CuCs-doped Ag-based promising catalysts for ethylene epoxidation[ACS Catal.11,3371(2021)].The theoretical results were based on surface modeling,while in the actual rea...Our recent theoretical studies have screened out CuCs-doped Ag-based promising catalysts for ethylene epoxidation[ACS Catal.11,3371(2021)].The theoretical results were based on surface modeling,while in the actual reaction process Ag catalysts are particle shaped.In this work,we combine density functional theory(DFT),Wulff construction theory,and micro kinetic analysis to study the catalytic performance of Ag catalysts at the particle model.It demonstrates that the CuCs-doped Ag catalysts are superior to pure Ag catalysts in terms of selectivity and activity,which is further proved by experimental validation.The characterization analysis finds that both Cu and Cs dopant promote particle growth as well as particle dispersion,resulting in a grain boundary-rich Ag particle.Besides,CuCs also facilitate electrophilic atomic oxygen formation on catalyst surface,which is benefitial for ethylene oxide formation and desorption.Our work provides a case study for catalyst design by combining theory and experiment.展开更多
Various scaling relations have long been established in the field of heterogeneous catalysis,but the resultant volcano curves inherently limit the catalytic performance of catalyst candidates.On the other hand,it is s...Various scaling relations have long been established in the field of heterogeneous catalysis,but the resultant volcano curves inherently limit the catalytic performance of catalyst candidates.On the other hand,it is still very challenging to develop universal descriptors that can be used in various types of catalysts and reaction systems.For these reasons,several strategies have recently been proposed to break and rebuild scaling relations to go beyond the top of volcanoes.In this review,some previously proposed descriptors have been briefly introduced.Then,the strategies for breaking known and establishing new and more generalized scaling relations in complex catalytic systems have been summarized.Finally,the application of machine-learning techniques in identifying universal descriptors for future computational design and high-throughput screening of heterogeneous catalysts has been discussed.展开更多
Exploring effective transition metal single-atom catalysts for selective oxidation of benzene to phenol is still a great challenge due to the lack of a comprehensive mechanism and mechanism-driven approach.Here,robust...Exploring effective transition metal single-atom catalysts for selective oxidation of benzene to phenol is still a great challenge due to the lack of a comprehensive mechanism and mechanism-driven approach.Here,robust 4N-coordinated transition metal single atom catalysts embedded within graphene(TM_(1)-N_(4)/C)are systematically screened by density functional theory and microkinetic modeling approach to assess their selectivity and activity in benzene oxidation reaction.Our findings indicate that the single metal atom triggers the dissociation of H_(2)O_(2)to form an active oxygen species(O*).The lone-electronic pair character of O*activates the benzene C–H bond by constructing C–O bond with C atom of benzene,promoting the formation of phenol products.In addition,after benzene captures O*to form phenol,the positively charged bare single metal atom activates the phenol O–H bond by electron interaction with the O atom in the phenol,inducing the generation of benzoquinone by-products.The activation process of O–H bond is accompanied by H atom falling onto the carrier.On this basis,it can be inferred that adsorption energy of the C atom on the O*atom(EC)and the H atom on the TM_(1)-N_(4)/C(EH),which respectively represent activation ability of benzene C–H bond and phenol O–H bond,could be labeled as descriptors describing catalytic activity and selectivity.Moreover,based on the as-obtained volcano map,appropriate EC(–8 to–7 eV)and weakened EH(–1.5 to 0 eV)contribute to the optimization of catalytic performance for benzene oxidation to phenol.This study offers profound opinions on the rational design of metal single-atom catalysts that exhibit favorable catalytic behaviors in hydrocarbon oxidation.展开更多
基金This work is supported by PetroChina Innovation Foundation(2019D-5007-0403).
文摘Our recent theoretical studies have screened out CuCs-doped Ag-based promising catalysts for ethylene epoxidation[ACS Catal.11,3371(2021)].The theoretical results were based on surface modeling,while in the actual reaction process Ag catalysts are particle shaped.In this work,we combine density functional theory(DFT),Wulff construction theory,and micro kinetic analysis to study the catalytic performance of Ag catalysts at the particle model.It demonstrates that the CuCs-doped Ag catalysts are superior to pure Ag catalysts in terms of selectivity and activity,which is further proved by experimental validation.The characterization analysis finds that both Cu and Cs dopant promote particle growth as well as particle dispersion,resulting in a grain boundary-rich Ag particle.Besides,CuCs also facilitate electrophilic atomic oxygen formation on catalyst surface,which is benefitial for ethylene oxide formation and desorption.Our work provides a case study for catalyst design by combining theory and experiment.
基金supported by the National Natural Science Founda-tion of China(21473053,91645122,and 22073027)the Natural Science Foundation of Shanghai(20ZR1415800)the Funda-mental Research Funds for the Central Universities(222201718003).
文摘Various scaling relations have long been established in the field of heterogeneous catalysis,but the resultant volcano curves inherently limit the catalytic performance of catalyst candidates.On the other hand,it is still very challenging to develop universal descriptors that can be used in various types of catalysts and reaction systems.For these reasons,several strategies have recently been proposed to break and rebuild scaling relations to go beyond the top of volcanoes.In this review,some previously proposed descriptors have been briefly introduced.Then,the strategies for breaking known and establishing new and more generalized scaling relations in complex catalytic systems have been summarized.Finally,the application of machine-learning techniques in identifying universal descriptors for future computational design and high-throughput screening of heterogeneous catalysts has been discussed.
基金Fundamental Research Funds for the Central Universities(Grant No.23CX07009A)National Natural Science Foundation of China(Grant No.22108305)+1 种基金Natural Science Foundation of Shandong Province(Grant No.ZR2023YQ009)Special Project Fund of Taishan-Scholars Shandong Province(Grant No.tsqn202211078).
文摘Exploring effective transition metal single-atom catalysts for selective oxidation of benzene to phenol is still a great challenge due to the lack of a comprehensive mechanism and mechanism-driven approach.Here,robust 4N-coordinated transition metal single atom catalysts embedded within graphene(TM_(1)-N_(4)/C)are systematically screened by density functional theory and microkinetic modeling approach to assess their selectivity and activity in benzene oxidation reaction.Our findings indicate that the single metal atom triggers the dissociation of H_(2)O_(2)to form an active oxygen species(O*).The lone-electronic pair character of O*activates the benzene C–H bond by constructing C–O bond with C atom of benzene,promoting the formation of phenol products.In addition,after benzene captures O*to form phenol,the positively charged bare single metal atom activates the phenol O–H bond by electron interaction with the O atom in the phenol,inducing the generation of benzoquinone by-products.The activation process of O–H bond is accompanied by H atom falling onto the carrier.On this basis,it can be inferred that adsorption energy of the C atom on the O*atom(EC)and the H atom on the TM_(1)-N_(4)/C(EH),which respectively represent activation ability of benzene C–H bond and phenol O–H bond,could be labeled as descriptors describing catalytic activity and selectivity.Moreover,based on the as-obtained volcano map,appropriate EC(–8 to–7 eV)and weakened EH(–1.5 to 0 eV)contribute to the optimization of catalytic performance for benzene oxidation to phenol.This study offers profound opinions on the rational design of metal single-atom catalysts that exhibit favorable catalytic behaviors in hydrocarbon oxidation.
