(535g) In Situ Ftir Study of Catalytic Partial Oxidation of Methanol on Pt/Al2O3

Methanol is considered as a good renewable energy source for hydrogen fuel cell systems. Catalytic partial oxidation (CPO) of methanol offers the potential of producing hydrogen supply for these systems through an exothermic reaction. However, the mechanism of methanol CPO is not completely understood due to its complexity: many primary reactions are likely involved. In this work, methanol CPO on Pt/Al2O3 catalysts was studied using in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS).

Methanol adsorption experiments were conducted on different catalyst states. Methoxy species, CH3Oad, were formed during dissociative adsorption of methanol on the catalysts. More and more formate adspecies was formed with increasing temperature under the methanol and helium mixture. The formate was probably formed from the methoxy groups adsorbed on the catalysts. Ignition of CPO was also studied, and it was found to occur at room temperature on both reduced and oxidized powder catalysts. Adsorbed formate disappeared during this process, while adsorbed CO species and CO2 gas were detected in the products.

CPO was studied at different temperatures from 723K to 1023K, and for methanol to oxygen mole ratios from 2 to 4. It was found that CO2 was the dominant products at lower temperatures and H2 and CO had a higher selectivity at higher temperatures. Fuel lean conditions favored H2 and HCOOH production. CO2 and CH3COOH increased when O2 concentration increased in the reaction mixture. According to the results, it is suggested that formate was one of the important intermediates in the H2 production pathway.