Rh-Ag/SiO_2催化剂上CO的吸附与加氢反应

Adsorption and Hydrogenation of CO over Rh Ag/SiO 2 Catalyst

应用表面反应红外动态技术考察了促进型铑催化剂Ｒｈ－Ａｇ／ＳｉＯ２上ＣＯ吸附及其加氢反应的性能，结果表明：线式吸附态的ＣＯ对氢的反应性能高于桥式吸附的ＣＯ，是加氢反应的主要活性吸附态．反应条件下温度升高有利于Ｒｈ－Ａｇ／ＳｉＯ２上线／桥ＣＯ吸附态强度比值的增加．表面反应生成了表面甲酰基、甲酸盐、乙酰基、乙酸盐、乙烯酮及烯醇盐等关键的Ｃ１－２含氧中间体．助剂Ａｇ的加入提高了铑催化剂上ＣＯ吸附态的线／桥强度比值以及线式吸附ＣＯ的加氢反应速率和Ｃ２含氧物的生成率．

Surface reaction infrared dynamic technique was used to examine the CO adsorption and the hydrogenation properties over promoted rhodium catalyst,Rh Ag/SiO 2. The result indicated that reactivity of the linear CO with hydrogen was higher than that of the bridged CO,and that the linear CO was the major active adsorbed species in the hydrogenation. Increase in temperature favored increase in the intensity ratio of linear to bridged CO bands on Rh Ag/SiO 2. Some C 1 2 oxygenated intermediates, such as surface formyl, formate,acetyl, acetate, ketene and enolate,appeared in the surface reaction. Addition of promoter Ag was in favor of increasing the linear to bridged intensity ratio of the CO adsorption state,and thus the rates of CO hydrogenation and the formation of C 2 oxygenate on the Rh catalyst.