摘要
选择性加氢制甲醇是CO_(2)资源化利用最主要的方式之一,因此十分需要开发高效的合成甲醇催化剂。本研究采用共沉淀法在In_(2)O_(3)中掺杂Sn来调控In_(2)O_(3)的还原能力和表面氧空位浓度,以提升In_(2)O_(3)催化剂在CO_(2)加氢制甲醇中的催化性能。通过XRD、TEM、H_(2)-TPR、H_(2)-D_(2)-TPSR、Raman、XPS、CO_(2)-TPD等表征手段,研究了Sn助剂对催化剂结构和表面化学性质的影响;并通过高压固定床装置测试了催化剂的催化性能。结果表明,Sn在In_(2)O_(3)中高度分散并倾向于在表面富集,与In_(2)O_(3)形成Sn—O—In结构,促进了表面氧空位的生成,且能抑制In_(2)O_(3)的过度还原,从而使得Sn-In_(2)O_(3)催化剂表现出更高的甲醇选择性和产率。在300℃、3 MPa、空速为15000 ml·g^(-1)·h^(-1)的反应条件下,Sn/In摩尔比为0.5%的Sn-In_(2)O_(3)催化剂具有最优的催化性能,此时CO_(2)转化率为6.2%,甲醇选择性为70.4%,当Sn含量进一步增加时,CO_(2)转化率会略有下降,而甲醇选择性提升至80.8%。
Selective hydrogenation of CO_(2)to methanol is one of the most important ways of resource utilization of CO_(2),so it is very necessary to develop efficient methanol synthesis catalysts.In this study,the Sn promoter has been incorporated into In_(2)O_(3)to modify its reducibility and the surface oxygen vacancy,in order to optimize the catalytic performance of In_(2)O_(3)catalyst for CO_(2)hydrogenation to methanol.Several characterizations including XRD,TEM,H_(2)-TPR,H_(2)-D_(2)-TPSR,Raman,XPS,and CO_(2)-TPD were conducted to reveal the effect of Sn promoter on the structure and chemistry of the catalysts.The activity tests were performed in a high pressure fixed-bed reactor to study the catalytic performance.The results showed that the Sn atoms were highly dispersed in In_(2)O_(3)and tended to accumulate on the surface through forming Sn—O—In structure,which promotes the formation of surface oxygen vacancy,and can inhibit the excessive reduction of In_(2)O_(3).As a result,the Sn promoted In_(2)O_(3)catalysts exhibited higher methanol selectivity and productivity.The Sn-In_(2)O_(3)catalyst with a Sn/In molar ratio of 0.5%possessed the optimized catalytic performance,which showed a CO_(2)conversion of 6.2%and methanol selectivity of 70.4%at the reaction conditions of 300℃and 3 MPa with GHSV of 15000 ml·g^(-1)·h^(-1).With further increment of Sn content,the CO_(2)conversion would slightly decrease,while the methanol selectivity would increase to 80.8%,significantly higher than that of 55.4%on the pure In_(2)O_(3)catalyst.
作者
杨菲菲
赵世熙
周维
倪中海
YANG Feifei;ZHAO Shixi;ZHOU Wei;NI Zhonghai(School of Chemical Engineering and Technology,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China;China Nuclear Power Engineering Co.,Ltd.,Beijing 100840,China)
出处
《化工学报》
EI
CSCD
北大核心
2023年第8期3366-3374,共9页
CIESC Journal
基金
中央高校基本科研业务经费项目(2023QN1012,2021QN1046)
中国矿业大学安全学科群自主创新项目(2022ZZX03)
江苏省碳达峰碳中和科技创新专项资金项目(BE2022613)
江苏省自然科学基金项目(BK20231075)。
