摘要
考察了α-Ga_(2)O_(3)、β-Ga_(2)O_(3)和γ-Ga_(2)O_(3)对CO_(2)氧化乙苯脱氢制苯乙烯反应的催化性能,并通过N_(2)吸附、XRD、NH_(3)-TPD、CO_(2)-TPD、^(71)Ga MAS NMR和TGA等多种方法对不同晶相Ga_(2)O_(3)催化剂进行表征,探究了催化剂晶相结构与催化性能的关联。结果表明,Ga_(2)O_(3)的晶相结构与CO_(2)氧化乙苯脱氢性能密切相关,γ-Ga_(2)O_(3)表现出最佳的催化性能,在550℃乙苯转化率达54.7%,苯乙烯选择性为98.6%,循环使用6次后,催化活性仍无明显降低。γ-Ga_(2)O_(3)具有最多的中强酸位、最高的四配位Ga(Ⅳ)百分比和最大的比表面积与孔体积,有利于乙苯的吸附活化、C—H键的解离和催化剂容碳能力的提升,从而使其表现出最佳的催化性能。
The oxidative dehydrogenation of ethylbenzene(EB)to styrene(ST)by CO_(2)(CO_(2)-ODEB)was investigated overα-,β-andγ-Ga_(2)O_(3)catalysts with different crystal phases.The physical and chemical properties of the catalysts were characterized by N_(2)adsorption,XRD,NH_(3)-TPD,CO_(2)-TPD,^(71)Ga MAS NMR and TGA.It was found that the catalytic activity depended on the crystalline phase structure of Ga_(2)O_(3).The EB conversion and ST selectivity reach 54.7%and 98.6%,respectively,for CO_(2)-ODEB over the most efficient catalyst,γ-Ga_(2)O_(3),at 550℃.Furthermore,the catalytic activity is not significantly reduced even after six recycling cycles.The results showed thatγ-Ga_(2)O_(3)catalyst has the most medium-strong acid sites,the highest percentage of tetracoordinated Ga(Ⅳ)and the largest specific surface area and pore volume,which was conducive to the adsorption and activation of EB,the dissociation of C—H bond and the enhancement of carbon capacity of catalyst,resulting in the best catalytic activity and excellent cycling stability towards CO_(2)-ODEB.
作者
卫瑞麒
司智伟
陈树伟
潘大海
王英雄
李瑞丰
WEI Ruiqi;SI Zhiwei;CHEN Shuwei;PAN Dahai;WANG Yingxiong;LI Ruifeng(College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan 030024,China;College of Chemistry,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《应用化工》
北大核心
2025年第5期1113-1118,共6页
Applied Chemical Industry
基金
国家自然科学基金(22378286,21975174)
中央引导地方科技发展资金(YDZJSX2021A014)。
关键词
氧化镓
二氧化碳
乙苯
氧化脱氢
苯乙烯
gallium oxide
carbon dioxide
ethylbenzene
oxidative dehydrogenation
styrene
作者简介
卫瑞麒(1998-),男,山西运城人,在读硕士研究生,师从陈树伟教授,从事CO_(2)的催化转化与利用的研究。电话:17200610771,E-mail:wrq1010514895@163.com;通信作者:陈树伟(1968-),男,教授。E-mail:csw603@163.com。
