Revealing the anti-sintering phenomenon on silica-supported nickel catalysts during CO_(2)hydrogenation  

作　　者：Liuqingqing Yang Tiancheng Pu Feixiang Tian Yulian He Minghui Zhu 

机构地区：[1]State Key Laboratory of Chemical Engineering,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China [2]University of Michigan-Shanghai Jiao Tong University Joint Institute,Shanghai Jiao Tong University,Shanghai 200240,China [3]School of Chemistry and Chemical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Journal of Environmental Sciences》2024年第6期270-278,共9页环境科学学报（英文版）

基　　金：supported by the Shanghai Post-Doctoral Excellence Program(No.2021232);Y.He thanks the National Natural Science Foundation of China(No.22202131);the Shanghai Science and Technology Development Funds of“Rising Star”Sailing Program(No.22YF1419400)for the financial support;M.Zhu thanks the research funding sponsored by the National Natural Science Foundation of China(No.22078089);the Shanghai Special Program for Fundamental Research(No.22TQ1400100-7);the Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.22JC1400600)。

摘　　要：The CO_(2)catalytic hydrogenation represents a promising approach for gas-phase CO_(2)utilization in a direct manner.Due to its excellent hydrogenation ability,nickel has been widely studied and has shown good activities in CO_(2)hydrogenation reactions,in addition to its high availability and low price.However,Ni-based catalysts are prone to sintering under elevated temperatures,leading to unstable catalytic performance.In the present study,various characterization techniques were employed to study the structural evolution of Ni/SiO_(2)during CO_(2)hydrogenation.An anti-sintering phenomenon is observed for both 9%Ni/SiO_(2)and 1%Ni/SiO_(2)during CO_(2)hydrogenation at 400℃.Results revealed that Ni species were re-dispersed into smaller-sized nanoparticles and formed Ni^(0)active species.While interestingly,this anti-sintering phenomenon leads to distinct outcomes for two catalysts,with a gradual increase in both reactivity and CH_(4)selectivity for 9%Ni/SiO_(2)presumably due to the formation of abundant surface Ni°from redispersion,while an apparent decreasing trend of CH_(4)selectivity for 1%Ni/SiO_(2)sample,presumably due to the formation of ultra-small nanoparticles that diffuse and partially filled the mesoporous pores of the silica support over time.Finally,the redispersion phenomenon was found relevant to the H_(2)gas in the reaction environment and enhanced as the H_(2)concentration increased.This finding is believed to provide in-depth insights into the structural evolution of Ni-based catalysts and product selectivity control in CO_(2)hydrogenation reactions.

关 键 词：Carbon dioxide utilization CO_(2)hydrogenation Nickel-based catalysts Anti-sintering Structural evolution 

分 类 号：X701[环境科学与工程—环境工程]