Accurate modeling of catalytic reactions on undercoordinated sites requires accounting for the structural and ensemble-specific nature of the active sites.This study examines how common microkinetic modeling(MKM)assum...Accurate modeling of catalytic reactions on undercoordinated sites requires accounting for the structural and ensemble-specific nature of the active sites.This study examines how common microkinetic modeling(MKM)assumptions affect predicted kinetics and mechanisms on the stepped Pt(211)facet for the ethane dehydrogenation(EDH)and the ethane hydrogenolysis(EH).Six(211)MKMs were developed,differing in(i)the number of active sites represented,(ii)adsorbate site occupancy treatment,and(iii)inclusion of cross-facet interactions.These models are benchmarked against a particle-based microkinetic model(PB-MKM),which best represents step-edge behavior.MKM assumptions caused deviations in turnover frequencies exceeding ten orders of magnitude and led to contrasting mechanistic and selectivity predictions.Multi-site MKMs overestimate activity by inflating free site availability,single-site models underestimate activity,and uniform occupancy models overpredict coverage of multi-dentate intermediates,leading to reaction-specific artifacts.Overall,the Combined Site Edge Model(CSEM),a single-siteMKMaccounting for site occupancy and cross-facet interactions,most closely approximates PB-MKM predictions.All models predict similar kinetics when surfaces are clean or primarily occupied by monodentate species.This work provides practical guidance for selecting MKM frameworks for undercoordinated catalytic surfaces and highlights the critical role of modeling assumptions in catalytic predictions.展开更多
Strengthening the oxide-metal interfacial synergistic interaction in nanocatalysts is identified as potential strategy to boost intrinsic activities and the availability of active sites by regulating the surface/inter...Strengthening the oxide-metal interfacial synergistic interaction in nanocatalysts is identified as potential strategy to boost intrinsic activities and the availability of active sites by regulating the surface/interface environment of catalysts.Herein,the SnO_(2)/PtNi concave nanocubes(CNCs)enclosed by high-index facets(HIFs)with tunable SnO_(2)composition are successfully fabricated through combining the hydrothermal and self-assembly method.The interfacial interaction between ultrafine SnO_(2)nanoparticles and PtNi with HIFs surface structure is characterized by analytical techniques.The as-prepared 0.20%SnO_(2)/PtNi catalyst exhibits extraordinarily high catalytic performance for ethylene glycol electrooxidation(EGOR)in acidic conditions with specific activity of 3.06 mA/cm^(2),which represents 6.2-fold enhancement compared with the state-of-the-art Pt/C catalyst.Additionally,the kinetic study demonstrates that the strong interfacial interaction between SnO_(2)and PtNi not only degrades the activation energy barrier during the process of EGOR but also enhances the CO-resistance ability and long-term stability.This study provides a novel perspective to construct highly efficient and stable electrocatalysts for energy conversions.展开更多
基金supported by the Institute for Cooperative Upcycling of Plastics (iCOUP), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Contract DE-AC-02-07CH11358 (Ames National Laboratory)B.R. and W.Y. acknowledge support from the U.S. Department of Energy, Office of Basic Energy Science, Catalysis Science program, under award DE-SC0023376In addition, A.H. acknowledges partial support by the South Carolina Smart State Center for Strategic Approaches to the Generation of Electricity (SAGE). Computing resources are provided by the U.S. Department of Energy facility located at the National Energy Research Scientific Computing Center (NERSC) under projects m4562 and m4885 (2025), and ACCESS facilities located at the San Diego Supercomputer Center (SDSC) and the Rosen Center for Advanced Computing (RCAC) of Purdue University (grant no. TG-CTS090100). Finally, computing resources provided by the University of South Carolina’s High-Performance Computing (HPC) group are gratefully acknowledged.
文摘Accurate modeling of catalytic reactions on undercoordinated sites requires accounting for the structural and ensemble-specific nature of the active sites.This study examines how common microkinetic modeling(MKM)assumptions affect predicted kinetics and mechanisms on the stepped Pt(211)facet for the ethane dehydrogenation(EDH)and the ethane hydrogenolysis(EH).Six(211)MKMs were developed,differing in(i)the number of active sites represented,(ii)adsorbate site occupancy treatment,and(iii)inclusion of cross-facet interactions.These models are benchmarked against a particle-based microkinetic model(PB-MKM),which best represents step-edge behavior.MKM assumptions caused deviations in turnover frequencies exceeding ten orders of magnitude and led to contrasting mechanistic and selectivity predictions.Multi-site MKMs overestimate activity by inflating free site availability,single-site models underestimate activity,and uniform occupancy models overpredict coverage of multi-dentate intermediates,leading to reaction-specific artifacts.Overall,the Combined Site Edge Model(CSEM),a single-siteMKMaccounting for site occupancy and cross-facet interactions,most closely approximates PB-MKM predictions.All models predict similar kinetics when surfaces are clean or primarily occupied by monodentate species.This work provides practical guidance for selecting MKM frameworks for undercoordinated catalytic surfaces and highlights the critical role of modeling assumptions in catalytic predictions.
基金the National Natural Science Foundation of China(No.21573286)the Key Scientific and Technological Innovation Project in Shandong Province(No.2019JZZY010343).
文摘Strengthening the oxide-metal interfacial synergistic interaction in nanocatalysts is identified as potential strategy to boost intrinsic activities and the availability of active sites by regulating the surface/interface environment of catalysts.Herein,the SnO_(2)/PtNi concave nanocubes(CNCs)enclosed by high-index facets(HIFs)with tunable SnO_(2)composition are successfully fabricated through combining the hydrothermal and self-assembly method.The interfacial interaction between ultrafine SnO_(2)nanoparticles and PtNi with HIFs surface structure is characterized by analytical techniques.The as-prepared 0.20%SnO_(2)/PtNi catalyst exhibits extraordinarily high catalytic performance for ethylene glycol electrooxidation(EGOR)in acidic conditions with specific activity of 3.06 mA/cm^(2),which represents 6.2-fold enhancement compared with the state-of-the-art Pt/C catalyst.Additionally,the kinetic study demonstrates that the strong interfacial interaction between SnO_(2)and PtNi not only degrades the activation energy barrier during the process of EGOR but also enhances the CO-resistance ability and long-term stability.This study provides a novel perspective to construct highly efficient and stable electrocatalysts for energy conversions.
