(526g) Zeolite-L and Zeolite-Y Supported Platinum Catalysts for Aqueous Phase Reforming of Methanol and Ethanol Solutions to Hydrogen

Aqueous phase reforming (APR) of biomass-derived carbohydrates may offer an alternative strategy for production of hydrogen from biomass and organic wastes. The APR processes can operate at low temperatures (<300oC) where the water gas shift reaction is also thermodynamically favored. Such a low temperature operation makes it capable of producing hydrogen streams with low carbon monoxide by single step in one reactor. However, due to the coexistence of H2 and CO/CO2 with various carbonaceous intermediates in the catalytic reactor, selectivity is a challenging issue in the APR process because formation of alkanes via methanation and Fisher-Tropsch reactions occurs at low temperatures. In this work, we evaluated the catalytic performance of zeolite-L and zeolite-Y supported Pt catalysts for APR of methanol and ethanol solutions. Both types of zeolite were found to be much better supports for Pt catalysts for APR compared to the conventional gamma-alumina supports. The acidity-basicity characteristics of the zeolites were found to influence the APR selectivity. Pt catalysts loaded in the basic KL and NaY zeolites exhibited higher hydrogen selectivity compared to those loaded in the acidic HL and HY zeolites. The HL and HY supported catalysts showed higher activity in catalyzing the dehydration of ethanol to form ethylene.