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利用TP-IR动态方法研究了0.7％Rh_2/Al_2O_3上CO吸附,CO和H_2共吸附的动态行为。结果表明,0.7％Rh_2/Al_2O_3上CO只有孪生吸附态,谱线出现在2087和2014cm~(_1)且孪生吸附态对应的Rh~I中心是稳定的。CO单独暴露于催化剂时,CO歧化在260℃以上发生。在室温CO和H_2(1:1)共吸附时,2050cm~(_1)新谱带出现,归属为Rh~I中心上形成羰基氢化物。动态过程中2050cm~(_1)谱带逐渐向低波数位移的行为归结为多氢羰基氢化物的形成。与CO单独吸附的结果相比较,作者认为在CO+H_2反应条件下,C—O键的削弱和断裂是经由多氢羰基氢化物途径,而不是经由C—O键直接断裂(CO解离或Bouduarol反应)途径。
The dynamic behavior of CO adsorption, CO and H 2 co-adsorption on 0.7% Rh 2 / Al 2 O 3 was studied by TP-IR dynamic method. The results show that there is only twin adsorption state on 0.7% Rh 2 / Al 2 O 3 and the spectrum appears at 2087 and 2014 cm -1. The Rh ~ I center corresponding to the twin adsorption state is stable. When CO is exposed to the catalyst alone, CO disproportionation occurs above 260 ° C. At room temperature CO and H 2 (1: 1) co-adsorption, 2050cm ~ (_1) new band appears, belonging to Rh ~ I center carbonyl hydride. The dynamic shift of the 2050 cm ~ (-1) band to the low wavenumber is attributed to the formation of polyhydrocarbon hydrides. In contrast to the CO sorption alone, the authors suggest that the weakening and breaking of the C-O bond under the CO + H 2 reaction is via a polyhydrocarbon hydride route rather than a direct cleavage via the C-O bond (CO dissociation or Bouduarol reaction) pathway.