In this work, we evaluate reaction mechanism and kinetics of propane dehydrogenation (PDH) over Pt single-atom-doped Cr₂O₃ catalyst by combining density functional theory calculations and microkinetic analysis. Pt single-atom-doped Cr₂O₃ achieves superior propane conversion and propene selectivity to PtSn alloy and pristine Cr₂O₃ under typical operating conditions. Pt serves as a promoter to activate nearby Cr-O Lewis-Pair sites. The promotion effect of Pt single-atom on activity is attributed to the lowered energy level of conduction band minimum of nearby O Lewis-base site, enhancing its H capture ability and accordingly facilitating first step of dehydrogenation of propane. The Pt single-atom promoter also enhances propene selectivity by adjusting the Cr-O Lewis acid-base interaction with the deep dehydrogenation product, impeding deep dehydrogenation process. This work provides theoretical insights into the feasibility of atom-level dispersion Pt promoter activating CrO_x-based catalysts for PDH process, and guidance for future rational design of other oxide-supported single-atom catalysts for PDH.

在这项工作中，我们通过结合密度泛函理论计算和微观动力学分析，评估了Pt单原子掺杂Cr ₂ O ₃催化剂上丙烷脱氢（PDH）的反应机理和动力学。在典型操作条件下，Pt 单原子掺杂的 Cr ₂ O ₃相对于 PtSn 合金和原始 Cr ₂ O _{3具有优异的丙烷转化率和丙烯选择性。}Pt 作为启动子激活附近的 Cr-O 路易斯对位点。Pt单原子对活性的促进作用归因于降低了O路易斯碱位附近的导带最低能级，增强了其H捕获能力，从而有利于丙烷脱氢的第一步。Pt单原子促进剂还通过调节Cr-O路易斯酸碱与深度脱氢产物的相互作用来增强丙烯选择性，从而阻碍深度脱氢过程。这项工作为PDH过程中原子级分散Pt促进剂活化CrO _{x基催化剂的可行性提供了理论见解，并为未来合理设计其他氧化物负载单原子PDH催化剂提供了指导。}