Effect of potassium on CO hydrogenation to isobutanol over Cu/Zn/La/ZrO2 catalyst
WU Yingquan1, ZHANG Tao1, ZHANG Junfeng1, WANG Liyan1,2,XIE Hongjuan1, YANG Guohui1, TAN Yisheng1,3*
(1 State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China;2 University of the Chinese Academy of Sciences, Beijing 100049, China;3 National Engineering Research Center for Coal-Based Synthesis, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China)
Abstract:
The alkaline promoter K modified Cu/Zn/La/ZrO2 catalysts were prepared using the coprecipitation method, and used for the synthesis of isobutanol from syngas in a fixed bed reactor. The effects of K promoter and reaction temperature on the catalytic performance were investigated in combination of BET, XRD, CO2-TPD, NH3-TPD and CO-TPD characterizations. The results indicated that addition of K inhibited the dispersion of each component, leading to the larger particle size. Meanwhile, reduction peaks of CuO shifted to the higher temperature. However, addition of K led to an increase in the amount of weak acidic sites and weak base sites, which have remarkably close relationships with CO adsorption and space-time yield (STY) of alcohol. Moderate weak acid and base sites were beneficial to improve the STY of total alcohols and the selectivity of isobutanol in total alcohols.
KeyWords:
alkaline metal; Cu/Zn/La/ZrO2 catalyst; syngas; isobutanol
