Catalyst for on-board reforming of methanol. Catalytic partial combustion and decomposition of methanol.

Abstract

In order to develop a catalyst and a system applicable to on-board reforming, catalytic conversion of methanol was investigated in an isothermal flow reactor. Among the catalysts tested, the highest activity for partial combustion of methanol was attained with a silica-supported copper-nickel catalyst, which was also active for decomposition of methanol. The X-ray analysis of the copper-nickel catalyst showed that the metals or their oxides were highly dispersed in the course of partial combustion of methanol. Methanol conversion on this catalyst increased with increasing partial pressure of oxygen. The enhanced reactivity of methanol in the presence of oxygen was interpreted by the following mechanism: methanol reacts very rapidly and selectively with oxygen to give a formaldehyde-type intermediate which decomposes to hydrogen and carbon monoxide. The stoichiometric reaction between methanol and oxygen proceeded completely at 200°C, while direct decomposition of methanol to hydrogen and carbon monoxide required much higher temperatures.