CO在铜基甲醇和低碳醇合成催化剂上吸附性能的研究

The adsorption of CO on Cu-base catalysts for methanol and low alcohol synthesis

应用程序升温脱附质谱检测(TPD-MS)、程序升温表面反应质谱检测(TPSR-MS)和透射红外光谱(FT-IR)等实验技术,研究比较了CO在铜基甲醇合成催化剂及其添钾改性的低碳醇合成催化剂上的吸附性能。结果发现,CO能同时吸附在Cu和ZnO上,由此提出了吸附态的CO能在Cu和ZnO上迁移的假设。钾的加入使催化剂表面产生了少量的Cu^+,但Cu^+吸附活化CO的能力不如Cu°强,认为Cu°起反应活性位的作用。钾的存在增强了CO在Cu上的吸附,且造成部分吸附的CO发生解离,并由此对C_2^+醇合成产生影响。

A combined technique employing TPD-MS.TPSR-MS and FT-IR has been used to study the adsorption of CO on Cu-ZnO-Al_2O_3 catalyst and Cu-ZnO-Al_2O_3-K_2O catalyst for synthesis of methanol and low alcohols respectively. It is discovered that CO can be adsorbed both on Cu and ZnO, and the adsorbed CO can migrate between Cu and ZnO. Adding potassium to Cu-ZnO-Al_2O_3 strengthens CO adsorption on Cu and increases the number of Cu^+ion on catalyst surface. However, the ability of Cu^+to adsorb and activate CO is weaker than that of Cu°. It is believed that Cu° is the main active site in the catalysts we used. At the same time,potassium causes a part of adsorbed CO discerped and takes part in forming C_2^+OH.