A novel approach has been proposed for mitigating the potassium deactivation in the K2CO3-catalyzed steam gasification of coal char by addition of Ca(OH)(2) in the char preparation. It was experimentally found that the Ca(OH)(2)-added char had higher reactivity for the catalytic gasification than the raw char. Ca(OH)(2) played a role in suppressing the interactions of K2CO3 with acidic minerals in coal during the gasification and also probably in forming more active oxygenated intermediate on the char surface. The distribution of gaseous products was examined during the catalytic gasification. An oxygen transfer and intermediate hybrid mechanism is applied for understanding of the rate and selectivity of the catalytic gasification. (c) 2009 Elsevier Ltd. All rights reserved.