Ni/CeO2@ZIF-8核壳结构催化剂的制备及其RWGS反应性能研究
Preparation of Ni/CeO2@ZIF-8 core-shell catalyst and its RWGS reaction performance
严琛 1刘新辉 1朱学栋 2杨帆2
作者信息
- 1. 华东理工大学 化工学院,上海 200237
- 2. 华东理工大学 化工学院,上海 200237;大型工业反应器工程教育部工程研究中心,上海 200237
- 折叠
摘要
利用液相浓度控制成核法制备了ZIF-8 包覆的Ni/CeO2 核壳结构催化剂,通过一系列表征技术,研究了ZIF-8 壳层对催化剂物理化学性质的影响,并进一步探究引入ZIF-8 对于催化剂上的RWGS反应性能与路径的影响.结果表明,ZIF-8 壳层能够增大催化剂的比表面积,减弱加氢能力和对CO的吸附强度,在 300℃,0.1 MPa,GHSV=6 L/(g·h)和CO2∶H2=1∶3的反应条件下,核壳结构催化剂上的CO选择性提升了60.3%.ZIF-8 包覆前后的Ni基催化剂上的反应中间物种不同,生成CO的主要中间体为羧酸盐而CH4 则为甲酸盐,ZIF-8 壳层的存在抑制了羧酸盐进一步加氢转化为甲酸盐,从而抑制了甲烷化副反应进行,提高了RWGS反应的CO选择性.
Abstract
The ZIF-8-coated Ni/CeO2 core-shell catalysts were prepared using a liquid phase concentra-tion controlled nucleation method.The effects of the ZIF-8 shell on the physicochemical properties of the catalysts were investigated by a series of characterization techniques,and the effects of introducing ZIF-8 on the performance and pathways of the RWGS reaction on the catalysts were further explored.The results showed that the ZIF-8 shell could increase the specific surface area of the catalysts,while weakening the hydrogenation capacity and the adsorption strength of CO,and the CO selectivity was enhanced by 60.3%under the reaction conditions of 300℃,0.1 MPa,GHSV=6 L/(g·h)and CO2∶H2=1∶3.The interme-diate species in the reaction on the Ni-based catalysts before and after ZIF-8 coating were different.The main intermediate for CO was carboxylate while the bridged formate was for CH4.The presence of the ZIF-8 shell inhibited the further hydrogenation of the carboxylate to formate intermediate species,thus inhibi-ting the methanation reaction from proceeding and improving the CO selectivity of the RWGS reaction.
关键词
Ni基核壳结构催化剂/ZIF-8/RWGS反应/CO选择性/反应路径Key words
Ni-based core-shell catalyst/ZIF-8/RWGS reaction/CO selectivity/reaction path引用本文复制引用
基金项目
国家自然科学基金(21776076)
中央高校基本科研业务费专项(JKA01211710)
出版年
2024
NETL
NSTL
万方数据