Ru-decorated N-doped carbon nanoflakes for selective hydrogenation of levulinic acid to ?-valerolactone and quinoline to tetrahydroquinoline with HCOOH in water

The effective dissociation of biomass-derived formic acid, as a sustainable hydrogen source, in water is explored for the hydrogenation of levulinic acid (LA) and quinoline. Ru decorated carbon nanoflakes prepared by car-boreduction (in Ar/H-2 atmosphere) of Ru containing N-doped carbon were used as catalysts. The successful formation of Ru-decorated N-doped carbons was confirmed by numerous spectroscopic tools. The catalyst exhibited outstanding activity and selectivity for the hydrogenation of LA and quinoline using formic acid as a hydrogen donor in water under mild conditions. The catalyst afforded 99.8% LA conversion and 100% selectivity for gamma-valerolactone (GVL), whereas 99.8% quinoline conversion and 93% selectivity for 1,2,3,4-tetrahydroquino-line (THQ) were obtained. Recycling experiments suggested that the catalyst was stable even after the 5 cycles. Various controlled experiments and characterizations were conducted to demonstrate the structure-activity relations and suggest plausible reaction mechanisms for the hydrogenation of LA and quinoline. The exploration of formic acid as a sustainable H-2 source and the development of metal decorated N-doped carbons for hydrogenation of LA and quinoline will be fascinating to catalysis researchers and industrialists.

Automated summary

The effective dissociation of biomass-derived formic acid in water for the hydrogenation of levulinic acid and quinoline was investigated using Ru decorated carbon nanoflakes as catalysts. The catalyst showed outstanding activity and selectivity, with high conversion and selectivity achieved for both levulinic acid and quinoline. The study provides insights into the use of formic acid as a sustainable hydrogen source and the development of metal decorated N-doped carbons for catalytic hydrogenation reactions.