(455a) Oxidative Reforming of Ethanol for Hydrogen Production On Fe/Ni/Cu Multicomponent Catalysts
Multicomponent catalysts containing Ni, Fe and Cu were prepared by combustion synthesis. The molar ratio of these elements was optimized for the ethanol reforming reaction. These catalysts were prepared from their nitrate precursors, and dissolved in water with an optimized amount of glycine which acts as a fuel for the combustion synthesis reaction as well as a reducing agent. This solution was then heated over a hotplate to ignite the mixture and produce via combustion the final crystalline material with the desired composition. The amount of glycine was adjusted based on previous work done in our group to get pure metals instead of metal oxides. The nature of combustion itself was found to be dependent on the fuel to oxidizer ratio. XRD and SEM results showing the effect of fuel to oxidizer ratio on the catalysts structure and morphology will be presented. Previous work on methanol reforming enabled us to modify the combustion process to design the appropriate catalysts for ethanol oxidative reforming. The activity of ethanol oxidative decomposition was measured in a multichannel reactor to optimize the activity as well as in a recycle reactor for kinetic studies. A complex CuxFeyNiz catalyst was found to be very active and selective for ethanol decomposition as well as ethanol partial oxidation. Hydrogen production started as 116 °C giving ~ 50% conversion and ~ 50% hydrogen selectivity at about 250 °C. In situ EXAFS was used to determine the oxidation state of the working catalysts, which along FTIR results, permitted to propose a reaction pathway consistent with the activity-selectivity results. These findings show that combustion synthesis can be used as an effective tool to design active and selective complex catalysts with tailored properties for hydrogen production from alcohols.
A. Kumar, A. S. Mukasyan, E. E. Wolf, Appl. Catal. A: Gen. 372 (2010), pp. 175-18