Pd-decorated CePO4catalyst for the One-Pot, Two-Step cascade reaction to transform biomass-derived furanic aldehydes into fuel intermediates

Abstract

Production of fuel range chemicals from biomassderived carbonyls is a viable strategy to overcome the dependency on nonrenewable fossil fuels. Acid−base catalytic processes play a vital role in producing liquid fuel range chemicals and intermediates derived from renewable biomass. Aldol condensation is one of the simplest ways to convert biomass-derived carbonyls to C8−C15 range fuels. Herein, CePO4 possessing acidic and basic sites is synthesized under basic pH and used as catalyst support to decorate Pd nanoparticles to fabricate a Pd/CePO4 catalyst. Pd/ CePO4 facilitates aldol condensation to form a highly selective α,βunsaturated methyl ketone in the first step, followed by the selective reduction of CC to form a C−C coupled hydrogenated product containing a CO functional group in a one-pot cascade protocol. Many biomass and non-biomass-derived aldehydes are reacted with acetone and methyl isobutyl ketone (MIBK) for the selective production of fuel precursors. Pyridine Fourier transform infrared (FT-IR) and NH3/CO2 temperature-programmed desorption (TPD) measurements are employed to probe the acidity and basicity of the catalyst. The influence of different Pd loadings on the reducibility of these catalysts is studied by H2 temperature-programmed reduction (TPR) analysis. The activation energy (Ea) for aldol condensation between furfural and acetone is estimated to be 55.3 kJ/mol. The present catalytic system offers a higher furfural conversion (99.0%) with a higher selectivity (93.6%) of the desired hydrogenated product. Production of furan-based higher-carbon-containing compounds having carbonyl functionality using a simple and robust metal phosphate-based catalyst would be highly interesting from industrial and academic perspectives for fuel/chemical production.