文献类型：期刊文献

中文题名：AgIr/MCM-41催化剂上CO催化氧化性能的研究

英文题名：Performance of AgIr/MCM-41 Catalysts for CO Oxidation

作者：范承德[1];唐璇[1];王丽[1];王海丰[1];詹望成[1];郭耘[1]

机构：[1]华东理工大学工业催化研究所

年份：2019

卷号：43

期号：7

起止页码：686

中文期刊名：稀有金属

外文期刊名：Chinese Journal of Rare Metals

收录：CSTPCD;;EI(收录号：20194507638564);Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：国家重点研发计划项目(2016YFC0204300);国家自然科学基金项目(21571061)资助

语种：中文

中文关键词：Ir纳米颗粒;AgIr双金属;一氧化碳氧化

外文关键词：Ir nanoparticles;AgIr bimetallic catalyst;CO oxidation

摘要：采用油胺合成法制备了粒度分布均匀的Ir纳米颗粒,透射电子显微镜(TEM)表明,更快的升温速率有利于合成更小的Ir纳米颗粒,近一步采用晶种生长法制备了AgIr双金属催化剂,再负载于MCM-41载体上,通过250℃以上的温度焙烧后,红外图谱表明AgIr双金属纳米颗粒表面并没发现C-H, C-N等键的存在,说明保护剂已基本去除,但高温焙烧又会导致AgIr双金属纳米颗粒发生了明显的团聚。研究了Ag的引入对Ir/MCM-41催化剂上CO氧化反应的影响,随着Ag含量的增加, AgIr双金属催化剂上CO的最低全转化温度逐渐升高,表明Ag的引入降低了Ir/MCM-41催化剂的CO催化氧化性能。通过O2程序升温脱附(O2-TPD),原位红外漫发射(in situ DRIFTS)进行了表征。研究发现,随着Ag的引入,削弱了AgIr/MCM-41金属催化剂上CO和O2的吸附强度,但却降低了催化剂对CO的氧化活性。理论计算表明, Ag的引入增加了CO氧化反应的活化能和增加了吸附O和CO之间的距离。
The Ir nanoparticles with uniform particle size distribution were prepared with oil amine synthesis method. Transmission electron microscope(TEM) images showed that the higher heating rate was better for smaller Ir nanoparticles. Ir nanoparticles were calcined at temperature above 250 ℃. There were no any sign of C-H, C-N detected by infrared spectroscopy, which showed that the protect reagent was moved from the surface of AgIr nanoparticles, but AgIr nanoparticles aggregated when the temperature of calcination was higher than 300 ℃. AgIr bimetallic catalyst were prepared by the seed-mediated growth. The effects of the presence of the Ag on Ir/MCM-41 for CO oxidation were investigated, and the CO total conversion temperature became higher as the increase of Ag amount, which showed that the addition of Ag lowered the activity of Ir/MCM-41 catalysts. Combined with the characterization results of the O2 temperature programmed desorption(O2-TPD) and in situ diffuse reflectance infrared Fourier transform spectroscopy(in situ DRIFTS), the deposition of Ag effectively weakened the adsorption strength of O2 and CO on AgIr/MCM-41, but decreased the activities for CO oxidation. The theoretical calculation results showed the presence of Ag increased the distance between the adsorbed O and CO on AgIr/MCM-41, which was suggested to be responsible for the increased activation energy of CO oxidation reaction.