Hydrogenolysis of cornstalk lignin in supercritical ethanol over N-doped micro-mesoporous biochar supported Ru catalyst

Biochar is a promising support to prepare metal-based catalysts due to its large surface area and special porous structure. This work proposed a novel Ru-based biochar catalyst by using KCl and melamine as templates to produce micro-mesoporous structure and realize N-doping at the same time. The prepared Ru/NMC catalyst showed a good hydrogenolysis performance of cornstalk lignin in supercritical ethanol. A series of catalyst characterizations were carried out to reveal the effects of micro-mesoporous structure and N-doping on the lignin hydrogenolysis. The micro-mesoporous structure led to a large surface area, which favored the dispersion of metal site and facilitated the mass transfer and diffusion during lignin hydrogenolysis, while the N-doping formed abundant edge N atoms, which promoted the interaction and the electron transfer between the loaded Ru and the support. These two crucial factors synergistically improved the lignin hydrogenolysis, with 31.2 wt% monomer yield at the reaction temperature of 260 C.