CU0.5Zn0.5Mn2O4 spinet-lattice catalyst has been studied for methanol decomposition by in situ infrared (IR) spectroscopy analysis and micro reactor study. Methoxy species is formed by dissociative adsorption of methanol which subsequently converts into formate species via step-wise dehydrogenation process. The activities of surface intermediates on reduced CuO, ZnO and Mn2O3 catalysts are strongly affected by the ease of hydrogen desorption from the site, the strength of C-H bonding and the availability of oxygen. A synergism between Cu and MnO whereby the Cu serves as a sink for reverse hydrogen atoms spillover from MnO has been proposed. The micro reactor analysis correlates well with the IR results. (c) 2007 Published by Elsevier B.V.