Ruthenium catalysts based on porous aromatic frameworks synthesized by modified impregnation methods for hydrogenation of levulinic acid and its esters

Ruthenium catalysts supported on porous aromatic frameworks (PAFs) were synthesized using different protocols for metal impregnation to achieve high catalytic performance in the hydrogenation of levulinic acid. Significant effect of the support modification with functional groups (amino-, sulfo-) was demonstrated. The main factors affecting the process including substrate concentration, temperature, reaction time and hydrogen pressure were investigated. Ruthenium catalyst Ru-PAF-30-SO3H (COD) based on PAF-30 modified with sulfo groups synthesized with the use of 1,5-COD was able to promote levulinic acid dimerization at high temperatures (200-250 degrees C).