【摘要】 利用程序升温表面反应─红外（ＴＰＳＲ－ＩＲ）动态技术考察ＣＯ吸附物种对氢的反应性能并检验表面反应生成的中间物，结果表明线式ＣＯ对氢的反应性能高于桥式ＣＯ，即线式ＣＯ更可能是活性吸附态；表面反应生成了ＨＣＯ、ＣＨ２等中间物．用键级守恒（ＢＯＣ）－Ｍｏｒｓｅ势方法计算比较了ＣＯ→ＣＨ２过程中各可能基元步骤在Ｒｈ（１１１）面上的反应活化能和反应热，结果表明ＣＯ经其部分氢化物种（如Ｈ２ＣＯ、ＨＣＯＨ）的氢解反应断裂Ｃ─Ｏ键在能量上最有利．根据这些实验结果，提出铑基催化剂上合成气转化反应主要按缔合式机理进行；ＣＯ的优势断键途径为先部分氢化，而后氢助断键．更多还原

【Abstract】 The main pathway for C-O bond cleavage in ethanol formation reaction has been studied by using TPSR-IR dynamic method and Bond-Order-Conservation(BOC)-Morse potential approach.The partially hydrogenated CO species, H CO(1589 cm(-1)),and CH2 species(2933 cm(-1))are simultaneously detected by IR in CO adsorption-TPSR(in H2 flow) dynamic process over Rh-Mn(1:1)/SiO2 catalyst,and a good correlation between the detected surface formyl intensity and the ethanol activity is also observed,implying that formyl species is a key intermediate in the ethanol synthesis and that C-O bond cleavage occurs from a partially hydrogenated CO species.BOC-Morse potential approach predicts the activation energies for C-O bond cleavage on Rh(111) surface according to dissociation mechanisms(including direct and hydrogen assisted dissociation of adsorbed CO)and association mechanisms(including direct and hydrogen assisted dissociation of partially hydrogenated CO such as H CO,H2 CO,HCOH),showing that the activation energy for hydrogen assisted dissociation of H2CO(or H COH)is the lowest. Based on the results of IR study and BOC calculation,it may be concluded that C-O bond cleavage occurs via hydrogen assisted dissociation of partially hydrogenated CO species.更多还原