【摘要】 探究催化剂表面吸附和催化反应机理对低碳烷烃脱氢催化剂理性设计具有非常重要的意义。本研究借助密度泛函理论（DFT）方法对Cr₂O₃（001）表面上异丁烷的吸附形态与位点及其脱氢反应机理进行了理论计算与能量分析。研究结果表明，异丁烷易于正面吸附于催化剂表面四配位Cr（4）处，分子轨道杂化是促使其稳定吸附的主要原因;与逐步脱氢反应机理相比，异丁烷同步脱氢反应能垒更低，故其更倾向于一步脱氢反应生成异丁烯。上述规律将为降低催化剂中铬含量或创制新型非贵金属催化剂提供理论指导。更多还原

【Abstract】 Insights into the mechanisms of surface adsorption and catalytic reaction are of great importance to the rational design of the catalysts for the light alkane dehydrogenation.In this study,the adsorption morphology,sites and dehydrogenation mechanism of isobutane on the Cr₂O₃（ 001） surface were theoretically investigated and analyzed by means of density functional theory（ DFT）.The results indicate that isobutane is apt to be adsorbed on the surface of the catalyst at the Tetra coordinated Cr（ 4） from the front side.The reason can be ascribed to the molecular orbital hybridization between isobutane and chromium.Compared to the step-by-step dehydrogenation reaction mechanism,the energy barrier in the one-step dehydrogenation process of isobutane is much lower.That is,isobutane is prone to be dehydrogenated with one-step mechanism to produce isobutene. These observations will provide theoretical guidance for the reduction of chromium content in chromium-based catalysts or the design and preparation of novel non-noble metal catalysts.更多还原