摘要
采用TPSR-MS及TPD-MS技术研究了Pd/CeO2-γAl2O3体系催化剂上表面氧物种脱附-恢复和甲醇表面反应性能,并以甲醇氧化反应为探针考察了催化剂在不同气氛下的氧化活性.结果表明,CeO2对γ-Al2O3载体的改性,有利于钯催化剂上表面氧物种的脱附和氧化再恢复,从而促进Pd/CeO2-γ-Al2O3催化剂对甲醇的完全氧化.甲醇在催化剂表面的程脱过程中均产生选择性氧化产物甲醛、甲酸、CO和CO2,CeO2的存在有利于甲醇的脱附及深度氧化,选择性氧化产物的脱附量明显减少,并发现CO2的脱附量及峰温次序与对甲醇的氧化活性一致.
In this paper,the desorption and surface reaction properties of CH3OH,the desorption and reproduction properties of surface oxygen over Pd/CeO2-γ-Al2O3,Pd/Al2O3 and CeO2-Al2O3 were investigated by means of TPSR-MS and TPD-MS.The oxidation activity of CH3OH on these catalysts was studied under different concentrations of oxygen.The results showed that CH2O,HCOOH and CO were generated in CH3OH-TPSR of the catalysts.The desorption and complete oxidation of CH3OH over Pd/Al2O3 were promoted in the case of adding CeO2,and the desorption amount of these associated by-products decreased evidently. It was found that the catalytic activities well agreed with the desorbed amount of CO2 and the order of peak temperature.The results of O2-TPD showed that CeO2 can promote the desorption and reproduction of the surface absorbed oxygen over Pd/Al2O3,and evidently increases the amount of surface oxygen.these results were closely relative to their activities.
出处
《杭州大学学报(自然科学版)》
CSCD
1996年第2期182-187,共6页
Journal of Hangzhou University Natural Science Edition
基金
浙江省科委基金
关键词
氧
脱附
甲醇
氧化
钯
氧化铈
催化剂
CeO_2
Pd
oxygen desorption-reproduction
mothanol oxidation