摘要
以Ni-Al水滑石为前驱体,采用水热合成法,制备了不同CeO_(2)含量的αCeO_(2)-Ni/Al_(2)O_(3)催化剂,通过XRD、N2吸附-脱附、CO_(2)-TPD和原位漫反射红外分析(DRIFT)等手段,表征了制备催化剂的微观结构和物化性质,评价了其对CO_(2)甲烷化反应的催化活性及稳定性,并进一步研究其催化CO_(2)甲烷化反应的机理。结果表明:制备催化剂主要为介孔结构,表面有较多的弱碱和中强碱性位点;CeO_(2)的适量引入可提高Ni-Al_(2)O_(3)催化剂低温催化CO_(2)甲烷化的活性,其中以CeO_(2)负载摩尔分数5%的催化剂性能最好,在250℃时,CO_(2)转化率可达91%,CH4选择性可达100%,且经120 h的稳定性测试后,活性无明显下降;CO_(2)甲烷化时,催化剂表面产生中间产物甲酸盐和双齿碳酸盐,其有利于CH4的生成。
With Ni-Al hydrotalcite as precursor,xCeO_(2)-Ni-Al_(2)O_(3) catalysts with different CeO_(2) loadings were prepared by hydrothermal synthesis method.Physicochemical properties of the catalysts were characterized by XRD,N2 adsorption-desorption,CO_(2)-TPD and DRIFT.Catalytic performance and stability of the catalysts in CO_(2) methanation were investigated and the reaction mechanism was further proposed.Results show that the proper introduction of CeO_(2) improves the low temperature activity of catalysts.When the loadings molar fraction of CeO_(2) is 5%,91%CO_(2) conversion and 100%CH4selectivity at 250℃are achieved,while the activity doesn’t decrease significantly after 120 h test.The pore structure of catalysts is still in the form of mesopores with more weak alkaline and medium-strong alkaline sites on the surface.DRIFT result shows that the intermediates,including formates and bidentate carbonates on the catalyst surface benefit CH4 formation.
作者
付长亮
张峻炜
王保玉
王宇飞
王勇
侯留成
FU Changliang;ZHANG Junwei;WANG Baoyu;WANG Yufei;WANG Yong;HOU Liucheng(School of Chemical Engineering and Food Science, Zhengzhou University of Technology, Zhengzhou 450044, China;Haohua-Junhua Group Co. Ltd., Zhumadian 463002, China)
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2022年第1期46-54,共9页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
河南省科技开放合作计划项目(172106000067)
河南省高等学校重点科研项目(21B550007)基金资助。
