PNNL

Abstract

Ethanol can be used as a platform molecule for synthesizing valuable chemicals and fuel precursors. Direct synthesis of C5+ ketones, building block for lubricants and hydrocarbon fuels, from ethanol was achieved over a stable Pd-promoted ZnO-ZrO2 catalyst. The sequence of reaction steps involved in the C5+ ketone formation from ethanol and the key reaction step was found to be the in situ generation of the acetone intermediate and the cross aldol condensation between the reaction intermediates acetaldehyde and acetone. The formation of Pd-Zn alloy in situ at the reaction condition was identified to be the key factor in maintaining high yield to the C5+ ketones and the stability to the catalyst. The yield of >70% to C5+ ketones was achieved over a 0.1%Pd-ZnO-ZrO2 mixed oxide catalyst, and the catalyst was demonstrated to be stable beyond 2500 hours on stream without any catalyst deactivation.