基于密度泛函理论研究H共吸附对丙烷脱氢的影响  

Study on H Co-adsorption Effect on Propane Dehydrogenation Based on Density Functional Theory

作　　者：杨明磊[1] 朱贻安[1] 周兴贵[1] 

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237

出　　处：《化学反应工程与工艺》2012年第4期289-293,共5页Chemical Reaction Engineering and Technology

基　　金：中央高校基本科研业务费(WA1014027)

摘　　要：采用密度泛函理论(DFT)考察了丙烷在Pt(111)表面上脱氢生成丙烯的反应机理。通过在Pt(111)面上预吸附一定数量H原子模拟共吸附H对丙烷脱氢过程的影响。结果表明:H共吸附能降低丙烷及其脱氢产物的吸附能,促进丙烯脱附,有利于提高丙烯的选择性;H共吸附会导致丙烷脱氢能垒变大,降低催化剂的脱氢活性;共吸附的影响随着H覆盖率增加而增大。The Density Functional Theory（DFT） calculations was conducted to investigate the reaction mechanism of propane dehydrogenation on Pt（Ⅲ）. Certain amount of H atoms were pre-adsorbed on the Pt（Ⅲ） surface to model the co-adsorption effect on propane dehydrogenation process. The results showed that the H co-adsorption could reduce adsorption energies of propane and dehydrogenation product, which indicated a lower barrier for propylene desorption resulting in higher propylene selectivity. The energy barrier for propane dehydrogenation increased due to H co-adsorption, which reduced the catalyst activity on the dehydrogenation process. The co-adsorption impact increased with the increase of H coverage.

关 键 词：丙烯选择性 密度泛函理论 氢共吸附 反应机理 

分 类 号：TQ323.8[化学工程—合成树脂塑料工业]