Upgrading of aromatic compounds in bio-oil over ultrathin graphene encapsulated Ru nanoparticles

Fast pyrolysis of biomass for bio-oil production is a direct route to renewable liquid fuels, but raw bio-oil must be upgraded in order to remove easily polymerized compounds (such as phenols and furfurals). Herein, a synthesis strategy for graphene encapsulated Ru nanoparticles (NPs) on carbon sheets (denoted as Ru[at]G-CS) and their excellent performance for the upgrading of raw bio-oil were reported. Ru[at]G-CS composites were prepared viathe direct pyrolysis of mixed glucose, melamine and RuCl sub(3) at varied temperatures (500-800 degree C). Characterization indicated that very fine Ru NPs (2.5 plus or minus 1.0 nm) that were encapsulated within 1-2 layered N-doped graphene were fabricated on N-doped carbon sheets (CS) in Ru[at]G-CS-700 (pyrolysis at 700 degree C). And the Ru[at]G-CS-700 composite was highly active and stable for hydrogenation of unstable components in bio-oil (31 samples including phenols, furfurals and aromatics) even in aqueous media under mild conditions. This work provides a new protocol to the utilization of biomass, especially for the upgrading of bio-oil.