Syngas, liquid fuels, and chemicals could be obtained through coal gasification. The catalytic effect of K2CO3 and CaCO3 on gasification with H2O/CO2 mixtures was studied in this research. The syngas production and char reactivity were compared with different gasifying atmospheres by using two catalysts. The H-2/CO mole ratio was between 0.5 and 3 by varying the H2O/CO2 ratios, which could be used for the chemical synthesis. Higher carbon conversion during char gasification was achieved with the mixed atmosphere (H2O/CO2 = 80/20) than with pure steam and CO2 atmospheres by using both catalysts. Further, the coal sample was investigated by Brunauer Emmett Teller measurements and emission scanning electron microscopy, and the higher surface area of coal particles and highly dispersed catalyst may be responsible for the observed higher reactivity with mixed gasifying agents.