Steam Reforming Reactions of Methanol Over Nickel and Copper Catalysts

Steam‐reforming reactions of methanol over NiO/Al₂O₃ and CuO/ZnO have been investigated. Over the nickel catalyst, the reaction rate is of zero kinetic order with respect to either methanol or steam, and the activation energy is 12.4 kJmol⁻¹, whereas with copper catalyst, the rate is expressed according to the literature as kP_a/(1 + K_aP_a + K_b+P_b) in which “a” and “b” are methanol and steam, respectively. The rate‐controlling step of the reaction is assigned to the dissociation of O‐H bond with dehydrogenation of C‐H bond proceed rapidly to form carbon oxides. With copper catalyst the intrinsic participation of a water molecule during the dehydrogenation of C‐H bond leads to the formation of carbon dioxide. With nickel catalyst, the dehydrogenation proceed more rapidly than the migration of a water molecule from an alumina site to a nickel site and causes almost exclusively the formation of carbon monoxide and hydrogen at a lower reaction temperature.