Oxidative Fluorination of Cu/ZnO Methanol Catalysts

The influence of a mild difluorine treatment on Cu/ZnO precatalysts for methanol synthesis was investigated. It led to the incorporation of 1.2…1.3±0.1 wt % fluoride into the material. Fluorination considerably increased the amount of ZnO x related defect sites on the catalysts and significantly increased the space‐time yields. Although the apparent activation energy E A,app for methanol formation from CO 2 and H 2 was almost unchanged, the E A,app for the reverse water‐gas shift (rWGS) reaction increased considerably. Overall, fluorination led to a significant gain in methanol selectivity and productivity. Apparently, also the quantity of active sites increased.