Immobilized highly dispersed Ni nanoparticles over porous carbon as an efficient catalyst for selective hydrogenation of furfural and levulinic acid

Sustainable catalysis is the key for the future progress toward biorefinery and bioeconomy. In this work, we designed and developed an inexpensive and eco-friendly Ni@C catalyst for selective hydrogenation of biomass-based platform molecules. A facile synthesized Ni nanoparticles encapsulated in a stabilized carbon support derived from a sacrificial agent copolymer-gel was investigated in the hydrogenation of furfural (FA) to tetrahydrofurfuryl alcohol (THFOL) and levulinic acid (LA) to gamma-valeralactone (GVL). The aim is to study the two different reactions over a highly stabilized Ni nanoparticles embedded in the carbon matrix. The Ni@C was found to be active and selective in multi-catalyzed hydrogenation reactions. The Ni nanoparticles with small and ultra-fine sizes are highly dispersed over the carbon matrix. This was concluded through high-resolution micrography images (SEM, TEM) and XRD patterns. In both reactions, a complete conversion of furfural and levulinic acid was achieved with maximum selectivity over the Ni@C catalyst. The effect of reaction temperature, solvent type, reaction time, and H-2 pressure were also studied. Overall, optimized reaction conditions were determined, and the Ni@C is easily reusable and exceptionally durable in the studied reaction cycles. The apparent activation energies for FA hydrogenation to THFOL and LA hydrogenation to GVL are 15.4 kJ/mol and 33.6 kJ/mol, respectively.