دانلود رایگان مقاله کاتالیزور پوشش دو فلزی با انتخاب بالا و واکنش برای هیدروژناسیون فورفورال

Abstract

Silica-supported platinum overlayer on nickel (Ni@Pt) or copper (Cu@Pt) catalysts were synthesized and tested for furfural hydrogenation. H2 chemisorption and an ethylene hydrogenation descriptor showed weakened H2 binding strength of both overlayer catalysts compared to pure Pt, consistent with literature predictions. Cu@Pt showed higher turnover frequencies of furfural hydrogenation compared to pure Pt and pure Cu. This improved reactivity is likely due to fewer Pt sites being blocked by strong hydrogen adsorption as a result of decreased H2 binding strength of Pt overlayer compared to pure Pt.

4. Conclusions

Silica-supported bimetallic Ni@Pt and Cu@Pt overlayer catalysts were synthesized using the directed deposition technique. H2 chemisorption and ethylene hydrogenation reactivity indicated that H2 adsorption strength of overlaying Pt in Ni@Pt and Cu@Pt was reduced from the pure Pt, in agreement with literature predictions. Both overlayer catalysts showed higher reactivity in furfural conversion compared to their parent metals. This enhancement could be ascribed to the reduced binding strength of H2 on Pt surface, resulting in fewer Pt sites blocked by the strong H2 adsorption and increased Pt reactivity. Also, high furfuryl alcohol selectivity was obtained with the Cu@Pt overlayer catalyst as well as higher reactivity. This suggests the advantage of Pt overlayer catalysts to improve the reactivity without sacrificing the selectivity.