氢气活化在过渡金属氧化物催化的加氢反应中起到至关重要的作用.二氧化铈(CeO2)表面上氢气如何活化是乙炔加氢反应中的重要科学问题.本文利用密度泛函理论计算(DFT)的方法,系统研究了化学计量及有氧缺陷的CeO2(111)、(110)和(100)表面上氢气活化机理.氢气在化学计量的CeO2表面解离时仅形成羟基,而氧空位的存在可以有效促进氢气活化.CeO2-x(111)和(100)缺陷表面上H+和H-物种可以共存,而在CeO2-x(110)缺陷表面上只能观察到H+物种.化学计量及有氧缺陷的CeO2表面上氢气活化的结构敏感性与H+和H-吸附能有关,并由氧空位形成能以及Ce、O离子的电荷分布决定.该理论工作深入理解了二氧化铈基催化剂上氢气活化过程,为优化和设计高效加氢催化剂提供了理论支撑.“,”Hydrogen activation plays a pivotal role in hydrogenation reactions over transition metal oxide catalysts. Clarifying hydrogen activation over ceria oxide ( CeO2 ) is an important issue in the acetylene hydrogenation reaction. Employing density functional theory ( DFT) calculations, we studied hydrogen activation over stoichiometric and defective CeO2 ( 111 ) , ( 110 ) , and ( 100 ) surfaces. Hydrogen dissociates on the stoichiometric CeO2 surfaces only forming hydroxyl groups. The presence of oxygen vacancies can promote the H2 activation over the defective CeO2 surfaces. Both H+and H-species can be found on the defective CeO2(111) and (100) surfaces, whereas only H+species can be observed on the defective CeO2(110) surface. The structure sensitivity of the H2 activation over the stoichiometric and defective CeO2 surfaces is correlated with H+and H-adsorption energies determined by the ability of the surface oxygen vacancy formation and charge distributions of Ce and O ions. Our work provides more insight into H2 activation on CeO2-based catalysts which will guide better catalyst design for hydrogenation reactions.