Porous Graphitized Carbon Supported Catalysts for Lignin Depolymerization in Hydrothermal Conditions

Graphitized porous carbon supports was incorporated with dispersed catalytic sites, i.e. transition metal (Ni/Fe) through in-situ thermochemical synthesis or liquid-reduction deposition. The graphene structure and  nano-scale active metal particles were characterized with TEM, SEM, XRD, Raman, TGA/DSC, physical and chemical adsorption. The advantages of  in-situ thermochemical synthesis approach are in scalable chemical modification at the nanoscale and in tuning the surface active groups for selective lignin conversion. We assume that catalytically active metals distributed in porous grahitized carbon matrix will result in  higher selective of lignin liquefaction and specific reaction pathways towards formation of aromatic derivatives in hydrothermal conditions. Lignin depolymerization products were analyzed and quantified with GC-MS. Mechanism of catalysts' deactivation was discussed based on characterization of fresh and used catalysts.