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用共沉淀法和浸渍法制备了一系列过渡金属复合物催化剂Kx/Cu-Fe-Zn,通过对催化剂进行了BET,H2-TPR,XRD,XPS,TEM等一系列物理化学性质的表征来探究了助剂K对催化剂的比表面积、还原行为、结构特性以及形貌等方面的影响.在固定床反应器上研究了碱金属助剂K的浸渍量以及温度对CO2加氢反应的催化活性,稳定性以及对产物分布的影响.研究发现,当温度为350℃,助剂K的浸渍量为K0.1/Cu-Fe-Zn时,催化剂的催化活性达到最高,CO2的转化率可以达到68.7%,进一步增加催化剂中K的含量时,催化剂的催化活性出现缓慢下降趋势.研究还发现随着助剂K的浸渍量的增加,CO2加氢反应中大分子量化合物增加,碳链增长,并且有大量高级醇和含氧化合物的形成.我们还讨论了在助剂K存在下催化剂上CO2加氢反应机理.
A series of Kx / Cu-Fe-Zn catalysts were prepared by coprecipitation method and impregnation method. The catalysts were characterized by a series of physicochemical properties such as BET, H2-TPR, XRD, XPS and TEM The influence of the additive K on the specific surface area, reduction behavior, structural properties and morphology of the catalyst was studied.The impregnation amount of alkali metal promoter K and the catalytic activity of temperature on the hydrogenation of CO2 were studied in a fixed bed reactor, Stability and product distribution.The results show that when the impregnation amount of K is K0.1 / Cu-Fe-Zn at 350 ℃, the catalyst has the highest catalytic activity and the conversion of CO2 can reach 68.7 %, Further increase the content of K in the catalyst, the catalytic activity of the catalyst showed a slow decline.The study also found that with the increase of the impregnation amount of the additive K, the carbon molecular weight of the CO2 hydrogenation reaction increases, and the carbon chain increases A large number of higher alcohols and oxygenates were formed. We also discussed the mechanism of CO2 hydrogenation over the catalyst in the presence of an auxiliary, K.