γ-valerolactone, a levulinic acid derivative, is a promising intermediate in the production of fuels and chemicals from lignocellulosic biomass. Over silica-alumina, γ-valerolactone undergoes ring opening, to form pentenoic acid, and decarboxylation, to form butene - which is readily converted to long-chain olefins (jet fuel) by oligomerization - and CO2. Herein, we present a fundamental study of the catalytic interconversion of γ-valerolactone and pentenoic acid and the decarboxylation of each species. Ring opening and ring closure occur rapidly at conditions typical of decarboxylation, and we have demonstrated that both direct decarboxylation of γ-valerolactone and indirect decarboxylation of the pentenoic acid intermediate are significant contributors to the net rate of butene production. Further, we demonstrate that each species interacts strongly with the catalyst surface and provide a description of parallel decarboxylation pathways proceeding through intermediates bearing β-carbenium ions, which allow for selective decarboxylation of either the lactone or the acid.
ASJC Scopus subject areas
- Chemical Engineering(all)