甲烷在ZnO表面反应制合成气的微观机理研究  

Microscopic study of syngas production by methane reaction on ZnO surface

作　　者：黄琼谊 楼波[1] 丁佳欣 王水安 HUANG Qiong-Yi;LOU Bo;DING Jia-Xin;WANG Shui-An(School of Electric Power,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学电力学院,广州510640

出　　处：《原子与分子物理学报》2025年第6期1-9,共9页Journal of Atomic and Molecular Physics

基　　金：广东省自然科学基金(2021B7575020071)。

摘　　要：利用密度泛函(DFT)和过渡态理论对甲烷分子在ZnO表面的微观反应过程进行第一性原理研究,通过建立ZnO表面的吸附模型,计算了吸附能、过渡态参数和态密度,探讨了甲烷分子在氧化锌晶体表面H解离以及H_(2)和CO的生成过程,结果表明:CH_(4)在ZnO(010)表面的最佳吸附位点为Zn位,吸附能为-4.65 kcal/mol,甲烷在氧化锌ZnO(010)面四次解离H(反应动力学上最有利路径)所需克服的能垒分别为38.6 kcal/mol、90.8 kcal/mol、53.2 kcal/mol和35.8 kcal/mol,其中甲烷第二次解离H_(2)过程能垒最高,是反应过程的决速步,降低该基元反应的活化能是关键,而-OH的形成抑制了-CH_(3)的解离.氧空位的形成增加活性位点的数量与提高位点的活性.甲烷与氧化锌表面的反应有两次H_(2)生成反应,第一次生成H_(2)的反应难度较大.A first-principles study of the microreaction process of methane molecules on the surface of ZnO was carried out by using density functional(DFT)and transition state theories.By establishing an adsorption model on the surface of ZnO,the adsorption energy,the transition state parameters,and the density of states were calculated,and the processes of the dissociation of H from the surface of the ZnO crystals,as well as the generation of H_(2)and CO by the methane molecules were investigated,and the results showed that the CH_(4)on the ZnO(010)surface is the optimal adsorption site of Zn site with an adsorption energy of-4.65 kcal/mol,and the energy barriers to be overcome for the four dissociations of H(the kinetically most favorable pathway of the reaction)by methane on the ZnO(010)surface of ZnO are 38.6 kcal/mol,90.8 kcal/mol,53.2 kcal/mol,and 35.8 kcal/mol,respectively.Among them,the second dissociation of H_(2)from methane has the highest energy barrier and is the decisive speed step of the reaction process.Lowering the activation energy of the reaction of this radical is critical,while the formation of-OH inhibits the dissociation of-CH_(3).The formation of oxygen vacancies increases the number of active sites with increasing the activity of the sites.The reaction of methane with zinc oxide surface has two H_(2)generation reactions,the first one is more difficult to generate H_(2).

关 键 词：化学链重整 甲烷 反应机理 密度泛函理论 过渡态 

分 类 号：O474[理学—半导体物理]