(214c) Stability of Supported Metal Catalyst in Aqueous Phase Reactions

A significant challenge associated with the conversion of biomass-derived molecules is the need to perform the reactions in the condensed phase. This challenge is magnified when the solvent is water where metal oxide supports are typically not stable. Carbon supports are effective alternatives, but the chemistry of the carbon surfaces can be difficult to characterize. Additionally, control of the pore structures of carbon supports is less well developed than with metal oxides. To overcome these issues, metal catalysts on carbon over-coated silica were synthesized in which the chemistry of the carbon layer was controlled by the calcination conditions. Advanced solid state NMR techniques were utilized to extensively characterize the carbon over-layers allowing for systematic assessment of the impact of either oxygen or nitrogen heteroatoms on the hydrothermal stability of supported Pd nanoparticles. Utilizing the insights from those studies, extended aqueous-phase reaction testing of supported Pt and Ru catalysts was performed to assess the potential for their stable operation.