摘要
二氧化铈(CeO2)由于其优异的储氧性能在催化反应中有着广泛的应用。本文通过嫁接共聚反应合成的新型花状CeO2比普通CeO2具有更优异的氨气选择性催化还原(NH3-SCR)活性,在空速为53 000 h^-1,250~375℃温度区间内NOx转化率和选择性分别达到了90%和95%以上。扫描电子显微镜、透射电镜和比表面积结果表明花状CeO2样品相比于普通CeO2具有更好的分散性、更小的颗粒和较大的比表面积。X射线光电子能谱表明花状CeO2存在更多三价铈,会促进氧空位以及表面活性氧的生成,进而促进快速SCR反应的发生,提升花状氧化铈的NH3-SCR活性。氨气程序升温脱附结果则表明花状CeO2有着更多的酸性位数量,表明反应物更容易在花状CeO2上吸附。
Ceria(CeO2) has wide applications in catalytic reactions due to its outstanding oxygen storage capacity.A novel flower-like CeO2 synthesized by graft copolymerization reaction exhibited superior NH3-SCR activity,with NOx conversion of 90% and N2 selectivity of 95% under 250~375℃ at the space velocity of 53 000 h^-1Scanning electron microscopy,transmission electron microscopy and specific surface area results show that the flower-like CeO2 has better dispersion,smaller particles and larger specific surface areas than conventional CeO2.X-ray photoelectron spectroscopy implies that flower-like CeO2 has more unsaturated Ce^3+,which is beneficial to the formation of oxygen vacancies and surface active oxygen,and further promoting fast SCR reaction and NH3-SCR activity of the flower-like CeO2.The NH3-temperature programmed desorption results show that the flower-like CeO2 possesses more acidic sites,which indicates easier adsorption of reactants on the flower-like CeO2.
作者
从其良
马赫遥
杨鸣刚
王瑜钢
李素静
李伟
CONG Qi-liang;MA He-yao;YANG Ming-gang;WANG Yu-gang;LI Su-jing;LI Wei(Key Laboratory of Biomass Chemical Engineering of Ministry of Education,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,China)
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2020年第3期810-815,共6页
Journal of Chemical Engineering of Chinese Universities
基金
国家重点研发计划(2017YFC02100904,2017YFC0210403)
国家自然科学基金(21606195)。
