(532di) Shape-Selective Silver Catalysts for Ethylene Epoxidation

Ethylene oxide (EO) is one of the highest volume chemicals in the world and is typically produced with promoted silver-based catalysts. The selectivity of EO is highly dependent on the silver faceting of the catalyst nanoparticles¹. It has been shown theoretically that silver with (100) facets results in a higher EO selectivity compared to (111) facets, which are thermodynamically more stable². Silver nanowires and silver nanocubes have been previously synthesized to express predominantly (100) facets³. In this study, hydrothermal and modified polyol methods were utilized to synthesize silver nanowires and nanocubes. Some synthesis parameters, such as time and chemical concentrations were varied to investigate their effect on morphology, yield and dimensions of specific silver particles. These catalysts were then impregnated on α-alumina for catalytic evaluation to determine the effect of catalyst shape, faceting, and synthesis methodology on EO selectivity. Additionally, the addition of promoters to the catalyst will be investigated to further increase EO selectivity.

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