Effect of the Aromatic Content of Organosilica Supports on Aqueous Phase Phenol Hydrogenation

Abstract In this work, bridged polysilsesquioxanes with varying aromatic content were used as catalyst supports with active metal palladium (Pd) for aqueous phase phenol hydrogenation. Alkoxysilane precursors, bis (trimethoxy silyl ethyl) benzene (BTEB), and bis (trimethoxy silyl) ethane (BTE) were co‐condensed by sol‐gel synthesis to vary the aromatic content of the support. Pd supported on aryl‐bridged polysilsesquioxane (ABPS) showed the highest phenol conversion, while its non‐aromatic counterpart (Pd/ethylene‐bridged polysilsesquioxane (EBPS)) exhibited the lowest catalytic activity. Aromatic groups were responsible for better Pd dispersion and phenol adsorption. Thermal stability and structural integrity of the organosilica supports were also enhanced due to aromatic groups within the organosilica matrix.