The precursors (CuCl2·2H2O and KCl) were co-impregnated on the γ-Al2O3 with the calculated percentages, 5 wt% Cu, and 1.54 wt% K. After impregnation, the samples were put into the oven at 298 K for 10 h, after that, the samples were heated to 393 K with the ramping rate of...