(732c) Tuning the Surface Reactivity of Intermetallic Compounds Towards Carbon, Oxygen, and Hydrogen to Affect CO vs. CO2 Production in Wet Reforming of Hydrocarbons and Oxygenates

Intermetallic compounds (IMCs) comprised of atomically ordered mixtures of non-noble transition metals and post-transition metal or semimetal elements exhibit unique and tunable surface chemistry towards carbon, oxygen, and hydrogen that is of significant interest to the greater heterogeneous catalysis community. Building understanding of how to control the unique surface chemistry of these materials may enable fine control over reactions that involve C-H, C-O, and O-H cleavage or formation. This study focuses upon control of activity and selectivity of wet reforming catalysts for the production of H₂ from small oxygenates and saturated hydrocarbons. Specific focus has been drawn to understand dehydrogenation and surface oxidation kinetics such that CO-free reformate can be produced. The study employed the synthesis of well-defined IMC nanoparticles of specific bulk and surface composition, spectroscopic studies to understand surface composition, and computational surface science efforts to determine mechanisms and kinetically- and selectivity-controlling reaction steps. Dramatic control has been achieved over oxidation ability of the catalyst such that selectivity in the reaction can be controlled to produce synthesis gas or CO-free H₂. The catalysts developed also exhibit marked stability under reaction conditions. The ramifications of the study also extend to the reforming of large hydrocarbons such as those found in JP-8 fuels and the possibility of exhibiting sulfur tolerance.