CO在担载Ru催化剂上的吸脱附作用及其表面加氢反应

研究了担载于Al_2O_3和ZrO_2上的以Ru_3(CO)_(12)为前体的Ru]和以RuCl_3为前体的Ru催化剂的TPR特性、CO吸脱附行为及其表面加H_2反应。担载于Al_2O_3上的Ru]和Ru催化剂上部分物相较担载于ZrO_2上者难于还原。CO在氧化Ru]催化剂上主要以Ru(CO)yO_2表面络合物形式存在,在还原Ru]和Ru、以及氧化Ru催化剂上CO以吸附物种形式存在。在Ru离子上的CO比在Ru原子上者难于脱附。以ZrO_2为载体的Ru]和Ru催化剂上的CO加H_2生成CH_4的性能显著优于以Al_2O_3为载体者,担载Ru]催化剂上的CO加H_2性能略优于担载Ru催化剂。

ADSORETiON-DESORPTION AND SURFACE HYDROGENATION OF CO ON SUPPORTED Ru CATALYSTS

The reduction of Ru catalysts,the adsorption-desorption and the surface hydrogenation of CO on Ru/ZrO2 and Ru/Al2O3 using Ru3(CO)12 or RuCl3 as precursor were studied.The TM values of TPR peak of the (Ru) catalyst prepared from Ru3(CO)12 and the Ru catalyst prepared from RuCl3 supported on A12O3 are higher than those of the Ru supported on ZrO2.The IR bands of CO adsorbed on the supported oxidized (Ru) catalysts are similar to the carbonyl bands corresponding to oxidized Ru surface complex,and its surface structure is mainly in the form of Ru(CO)yO2.However,the IR bands of CO adsorbed on the supported reduced (Ru) catalysts attributed to adsorbed species of various forms are essentially the same as those of the supported Ru catalysts.The chemisorption and hydrogenation centers for CO on Ru/ZrO2 and (Ru)/ ZrO2 are more than those on Ru/Al2O3 and (Ru)/Al2O3.The hydroge-nated products are composed mainly of CH4 and trace CO2.The supported (Ru) catalysts are preferable to the supported Ru catalysts in the selectivity for CH4 production.