【摘要】 用程序升温表面反应（TPSR）法研究对比了在工业甲烷化镍催化剂上纯CO吸附,CO+H₂共吸附及CO+H₂在反应过程中的吸附。纯CO吸附态和CO+H₂共吸附态的TPSR谱较相似,都只有高温（350℃以上）和低温（约200℃）两个峰。而反应定态吸附态的TPSR谱有三个峰,发现其中温峰（300℃）与反应活性物种有联系。用D₂同位素研究了定态吸附态的组成,发现TPSR的三个峰的吸附态组成中都含有大量碳物种,少量的CH和CH₂物种;而且不同温度下出现的三个TPSR谱峰都含有大致接近的C,CH和CH₂物种,反映了同一物种的反应能力的差别,而不同的物种出现在同一温区内,意味着吸附物种的反应能力主要决定于金属—碳键的性质。更多还原

【Abstract】 Chemisorbed states formed on a commercial nickel catalyst during the adsorption of CO(Ⅰ),the co-adsorption of CO and H2 (1:1) at the temperature below methanation temperature(Ⅱ) and at the temperature above methanation temperature (Ⅱ) were investigated and compared with the aid of TPSR method. TPSR spectra of (Ⅰ) and (Ⅱ) were similar in their temperature patterns and were analogous to the results reported in literature. In both TPSR spectra of (Ⅰ) and (Ⅱ), appeared two peaks with one at high temperature (above 350℃)and another at low temperature (about 200℃), while in the spectra of (Ⅱ) there was an additional peak of medium temperature range (about 300℃), which was found to be close link with the reactive surface species. These results suggest that the adsorption states formed under reaction conditions are not always compatible with the adsorbed species observed under non-reacting conditions, and therefore it is important to study the adsorption species under steady-state reaction conditions.The composition of the adsorption species in case of(Ⅲ) was determined by using D2 isotope. It was found that among CDx species formed, the carbon species were most abundant, CH and CH2 species presented only in a small part. All of the three TPSR peaks appearing at different peak temperatures resulted from the methanation of carbon species as well as from CH and CH2 species and thus reflected different reactivity of the same surface species. And different carbon species appearing at one peak temperature implied that their reactivity depended mainly on the nature of the bonds between metal and carbon atom on the catalyst surface.更多还原