摘要
N_(2)O作为继CO_(2)和CH_(4)后的第三大温室气体,对大气环境危害极大。本文以表面活性剂F127为络合剂,采用溶胶-凝胶法制备了一系列Ag掺杂的钴基过渡金属氧化物催化剂3.0F-AgxCo(x=0~0.1),并用于直接催化分解N_(2)O的研究。研究发现,与3.0F-Co_(3)O_(4)相比,Ag以Ag_(2)O的形式高度分散在催化剂表面。助剂Ag的加入减小了Co_(3)O_(4)的平均晶粒尺寸,削弱了Co—O键,从而显著增强了催化剂的低温活性。同时,由于Co—O键的削弱促进了催化剂表面氧空位的再生,使得3.0F-Ag_(0.02)Co催化剂在反应中的活化能降低,并表现出更高的比反应速率。此外,3.0F-Ag_(0.02)Co催化剂在5%(体积分数)O_(2)+100μL/L NO+2%(体积分数)H_(2)O的共同影响下依然具有较高的催化活性和稳定性,在15h以上的稳定性测试中,400℃时仍能维持85%的N_(2)O转化率。
Nitrous oxide(N_(2)O)is the third greenhouse gas in amount,after carbon dioxide(CO_(2))and methane(CH_(4)),and has extremely harmful impact on environment.A series of Ag-doped cobalt based transition metal oxide catalysts(3.0F-AgxCo,x=0—0.1)were prepared by the sol-gel method using the surfactant F127 as the complexing agent and used for direct catalytic decomposition of N_(2)O.It was observed that Ag was highly dispersed on the catalyst surface in the form of Ag_(2)O.In comparison to 3.0FCo_(3)O_(4),the incorporation of Ag resulted in a reduction of the average grain size of Co_(3)O_(4) and a weakening of the Co—O bond,which significantly enhanced the low-temperature activity of the catalyst.Meanwhile,the weakening of the Co—O bond facilitated the regeneration of oxygen vacancies on the catalyst surface,resulting in a lower reaction activation energy and a higher specific reaction rate.Furthermore,the 3.0FAg_(0.02)Co catalyst displayed high catalytic activity and stability under 5%O_(2),100μL/L NO and 2%H_(2)O,maintaining a N_(2)O conversion of 85%for 15h at 400℃.
作者
张海鹏
秦珊珊
王俣萱
于海彪
ZHANG Haipeng;QIN Shanshan;WANG Yuxuan;YU Haibiao(Criminal Investigation Police University of China,Shenyang 110854,Liaoning,China;College of Chemistry,Liaoning University,Shenyang 110036,Liaoning,China)
出处
《化工进展》
北大核心
2025年第9期4999-5005,共7页
Chemical Industry and Engineering Progress
基金
国家自然科学基金(22006062)
辽宁省教育厅基础科研项目青年项目(LJKQZ2021021)。
