The promotional effect of K on the catalytic activity of Ni/MgAl2O4 for the combined H2O and CO2 reforming of coke oven gas for syngas production

A K-promoted 10Ni-(x)K/MgAl2O4 catalyst was investigated for the combined H2O and CO2 reforming (CSCR) of coke oven gas (COG) for syngas production. The 10Ni-(x)K/MgAl2O4 catalyst was prepared by co-impregnation, and the K content was varied from 0 to 5 wt%. The BET, XRD, H-2-chemisorption, H-2-TPR, and CO2-TPD were performed for determining the physicochemical properties of prepared catalysts. Except under the condition of a K/Ni=0.1 (wt%/wt%), the Ni crystal size and dispersion decreased with increasing K/Ni. The coke resistance of the catalyst was investigated under conditions of CH4: CO2: H-2: CO:N-2=1 : 1 : 2 : 0.3 : 0.3, 800 A degrees C, 5 atm. The coke formation on the used catalyst was examined by SEM and TG analysis. As compared to the 10Ni/MgAl2O4 catalyst, the Kpromoted catalyst exhibited superior activity and coke resistance, attributed to its strong interaction with Ni and support, and the improved CO2 adsorption characteristic. The 10Ni-1K/MgAl2O4 catalyst exhibited optimum activity and coke resistance with only 1wt% of K.