低碳化学与化工2026，Vol.51Issue(2)：31-38,8.DOI:10.12434/j.issn.2097-2547.20250107
Na助剂调控Fe(111)表面上CO2加氢制低碳烯烃反应路径及产物相对选择性的理论研究
Theoretical study on Na promoter-regulated reaction pathways and product relative selectivity of CO2 hydrogenation to light olefins on Fe(111)surface
摘要
Abstract
Fe-based catalysts,owing to the low cost and excellent catalytic performance,are widely used in CO2 hydrogenation to light olefins.Na can significantly increase the selectivity of light olefins,but the underlying mechanism remains unclear.The influence of Na as a promoter on the reaction pathways and product relative selectivities of CO2 hydrogenation to light olefins on the Fe(111)surface was studied by combining density functional theory(DFT)calculations and microkinetic modeling(MKM)analysis.DFT calculations show that Na doping modifies the electron density of the Fe(111)surface and significantly promotes CO2 adsorption and activation.Moreover,Na reduces the energy barriers of C2H4* formation and desorption from 0.81 eV and 1.10 eV to 0.61 eV and 0.46 eV,respectively,and increase the energy barrier of CH4 formation from 0.95 eV to 1.15 eV.MKM analysis shows that Na doping substantially increases the rates of C2H4* formation and desorption and reduces the rate of CH4 formation.The rate-determining step of the entire reaction network shifts from C2H4* formation and desorption to CH4 formation.The above results reveal the intrinsic mechanism that Na increases the rates of C2H4 formation and reduces the rates of byproduct CH4 formation to increase the C2H4 relative selectivity by regulating electronic structures of the Fe(111)surface at the molecular level.关键词
CO2加氢/Fe基催化剂/Na助剂/密度泛函理论/微观动力学分析Key words
CO2 hydrogenation/Fe-based catalysts/Na promoter/density functional theory/microkinetic modeling分类
化学化工引用本文复制引用
田佳荣,吴华帅,张效胜,丁传敏,王俊文..Na助剂调控Fe(111)表面上CO2加氢制低碳烯烃反应路径及产物相对选择性的理论研究[J].低碳化学与化工,2026,51(2):31-38,8.基金项目
国家自然科学基金(22308244) （22308244）
山西省基础研究计划(20210302123063). （20210302123063）
