Mechanism of dibenzofuran hydrodeoxygenation on the Ni(1 1 1)surface  

作　　者：Zi-Zheng Xie Meng Zhang Xing-Bao Wang Liang Guo Zhen-Yi Du Wen-Ying Li 

机构地区：[1]State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of TechnologyKey Laboratory of Coal Science and Technology(Taiyuan University of Technology),Ministry of Education,Taiyuan 030024,China

出　　处：《Chinese Journal of Chemical Engineering》2021年第7期204-210,共7页中国化学工程学报（英文版）

基　　金：financial support from the National Key Research and Development Program of China(2016YFB0600305);National Natural Science Foundation of China(21808153,22078220)。

摘　　要：The low-temperature coal tar contains a considerable number of oxygen-containing compounds,which results in poor quality.The catalytic hydrodeoxygenation of oxygen-containing compound to an added-value chemical compound is one of the most efficient methods to upgrade coal tar.In this study,density functional theory calculations are employed to assess and analyze in detail the hydrodeoxygenation of dibenzofuran,as a model compound of coal tar,on the Ni(111)surface.The obtained results indicate that dibenzofuran can be firstly hydrogenated to tetra hy d rod i be nzofura n and hexahydfodibenzofufan.The five-membered-ring opening reaction of tetrahydrodibenzofuran is more straightforward than that of hexahydrodibenzofuran(Ea=0.71 eV vs.1.66 eV).Then,both pathways generate an intermediate 2-cyclohexylphenoxy compound.One part of 2-cyclohexylphenoxy is hydrogenated to 2-cyclohexylphenol and consecutively hydrogenated to cyclohexylcyclohexanol,and another part is directly hydrogenated to cyclohexylcyclohexanone.The hydrogenated intermediates of2-cyclohexylphenol have higher deoxygenation barriers than 2-cyclohexylphenol and cyclohexylcy clohexanol.During the hydrogenation process of cyclohexylcyclohexanone to cyclohexylcyclohexanol,the intermediate 26,formed by adding H to O atom of cyclohexylcyclohexanone,exhibits the lowest deoxygenation barrier of 1.08 eV.High hydrogen coverage may promote the hydrogenation of tetrahydrodibenzofuran,hexahydrodibenzofuran,and intermediate 26 to generate dodecahydrodibenzofuran and cyclohexylcyclohexanol.This dibenzofuran hydrodeoxygenation reaction mechanism corroborates well with previous experimental results and provides a theoretical basis for further optimization of the design of nickel-based catalysts.

关 键 词：Oxygen-containing compound HYDROGENATION DEOXYGENATION CATALYSIS Computational chemistry 

分 类 号：TQ523.6[化学工程—煤化学工程] TQ426