Resource Utilization of Waste CeO2 -Based Deno(x) Composite Catalysts for Hydrogen Production Via Steam Reforming

Resource utilization of waste deNO(x) catalysts has become a major demand. A new resource utilization way of waste Ce-W-O-x/TiO2 (TCW) deNO(x) catalysts for steam reforming reaction using different hydrogen resources was verified. The waste TCW carrier supported NiO (N/TCW) exhibited excellent catalytic performance and formaldehyde was verified as the optimum hydrogen resource. The optimum N/TCW showed 104.5% H-2 selectivity at 500 degrees C and high H-2 production rate (13.1 L min(-1)). Its formaldehyde conversion was higher than 96.0% at the range of 450-600 degrees C. Analysis showed that the richness of hydroxyl group determined the reaction rate and selectivity. The enhancement of surface acid quantity and redox properties could improve the catalytic selectivity and activity. The in situ DRIFT study verified that water molecules must participate in the two types of reaction processes for the steam reforming reaction and the hydrogen bond accelerate the reaction by reducing reaction steps. The adsorbed formaldehyde species firstly converted to di-oxymethylene, then transformed to formate, species. Finally, the H-2 and CO2 generated by the dehydrogenation of intermediate. The solution can solve two problems at the same time: solid pollution of waste Ce-W-O-x/TiO2 catalyst and energy shortage.