摘要
采用等体积浸渍法制备了Bi改性的Pd-Au/A12O3催化剂,用低温氮吸附、CO-FTIR、H2-TPR等方法对催化剂进行了表征.CO-FTIR表征结果显示,随Bi含量的增加,以线性吸附的CO的比例增加,CO吸附峰随Bi含量的增加发生红移,说明Bi-Pd之间存在电子效应.H2-TPR表征结果显示,Bi改性后在催化剂表面形成了Pd-Au-Bi三元合金,因此改变了催化剂选择性加氢的活性.对改性前后Pd-Au/A12O3催化剂的异戊二烯选择性加氢活性评价结果表明,Bi的添加使催化剂对单烯烃的选择性提高,但同时活性下降;当反应温度为80℃时,随Bi含量的增加（w=0.1％～0.3％）,异戊二烯的转化率由98％降至34％,2-甲基-2-丁烯的选择性由82.3％降至68.6％,3-甲基-1-丁烯和2-甲基-1-丁烯的选择性分别由2.1％,13.3％增至8.6％,22.0％.
A series of Bi modified Pd-Au/A1203 catalysts were prepared by isometric impregnation and characterized by means of low temperature nitrogen adsorption, CO-FTIR and H2-TPR. The CO- FTIR results showed that, with increasing the content of Bi, the fraction of CO linearly adsorbed increased and the red shift of the CO adsorption peak appeared, which indicated that there was electronic effect between the Bi and Pd. The H2-TPR results showed that Pd-Au-Bi ternary alloy was formed, thus the catalytic properties of the catalysts may be improved. Compared with the Pd- Au/AI203 catalysts, the Pd-Au/Bi203-A1203 catalysts showed the high hydrogenation selectivity to isopentene and low activity. At 80 ~C, with increasing the content of Bi （0.1%-0.3%（w））, the isoprene conversion decreased from 98% to 34%, the selectivity to 2-methyl-2-butene decreased from 82.3% to 68.6%, but the selectivities to 3-methyl-1-butene and 2-methy-l-butene increased from 2.1% and 13.3% to 8.6% and 22.0%, respectively.
出处
《石油化工》
CAS
CSCD
北大核心
2014年第2期132-137,共6页
Petrochemical Technology
基金
国家重点基础研究发展计划项目(2010CB226905)
国家自然科学基金项目(21176258
U1162203)
关键词
钯-金
氧化铝催化剂
钯-金-铋三元合金
异戊二烯
选择性加氢
电子效应
palladium-gold/alumina catalysts
palladium-gold-bismuth ternary alloy
isoprene
selective hydrogenation
electronic effect
