Selective hydrogenation of acetylene on SiO_2-supported Ni-Ga alloy and intermetallic compound

作     者：Lei Wang Fengxu Li Yanjun Chen Jixiang Chen Lei Wang;Fengxu Li;Yanjun Chen;Jixiang Chen

作者机构：Tianjin Key Laboratory of Applied Catalysis Science and TechnologyDepartment of Catalysis Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin University 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2019年第28卷第2期

页      面：40-49页

核心收录：

学科分类：0820[工学-石油与天然气工程] 0808[工学-电气工程] 07[理学] 0817[工学-化学工程与技术] 0807[工学-动力工程及工程热物理] 070303[理学-有机化学] 0827[工学-核科学与技术] 0703[理学-化学] 

基　　金：supported by the National Natural Science Foundation of China (21576193) 

主　　题：Selective hydrogenation Acetylene Ni-Ga alloy Ni3Ga intermetallic compound 

摘      要：Ni/Si O_2 and bimetallic Ni_xGa/SiO_2 catalysts with different Ni/Ga atomic ratios(x = 10～2) were investigated for the selective hydrogenation of acetylene.It was found that Ni_xGa/SiO_2 showed higher selectivity to ethylene than Ni/Si O_2.This is attributed to the formation Ni-Ga alloy and Ni3 Ga intermetallic compound(IMC) where there was a charge transfer from Ga to Ni,which is favorable for reducing the adsorption strength and amount of ethylene on Ni atoms.As a result,the over-hydrogenation,the C–C bond hydrogenolysis and the polymerization were suppressed,and subsequently the selectivity to ethylene was enhanced.With the decrease of Ni/Ga atomic ratio,the activity and stability of the Ni_xGa/SiO_2 catalysts increased first and then decreased,while the ethylene selectivity tended to increase.Ni_5 Ga/SiO_2 exhibited the best performance.Under the conditions of 180 °C,0.1 MPa,and a reactant(1.0 vol% acetylene,5.0 vol% H_2 and 94 vol% N_2) with the space velocity of 36,000 m L h^(-1) g^(-1),the acetylene conversion maintained at 100% on Ni_5 Ga/SiO_2 during 120 h time on stream and the selectivity to ethylene was 75%～81%after reaction for 68 h.It was also found that the formation of Ni-Ga alloy and Ni_3 Ga IMC suppressed the incorporation of carbon to form NiCx,subsequently enhancing the catalyst stability.Additionally,with increasing the Ga content,the catalyst acid amount and strength tended to increase,which promoted the polymerization and carbon deposition and so the catalyst deactivation.