Transition metal carbide catalysts for Upgrading lignocellulosic biomass-derived oxygenates: A review of the experimental and computational investigations into structure-property relationships

Transition metal carbide (TMC) catalysts, due to their noble metal like characteristics,have emerged as potential candidates for the hydrodeoxygenation (HDO) of biomass derived species, including the pyrolysis product bio-oil. However, the selectivity for deoxygenation, excessive hydrogenation and stability under operating conditions,remain as key challenges. Hence, this paper presents a comprehensive review of the state of the art with regard to (i) the preparation and structure of TMCs, (ii) characterization of active sites on TMCs and (iii) fundamental knowledge of the reaction mechanisms/pathways and associated energetics of HDO of model compounds which are present in biomass derived bio-oil. We believe that this fundamental knowledge will greatly assist researchers to systematically modify the composition and structure of TMCs to optimize their HDO performance. [Display omitted] •Catalytic Hydrotreatment of pyrolysis bio-oil as a sustainable pathway to produce fuels and chemicals.•Transition metal carbides and their noble metal like properties.•Recent advances in the synthesis of transition metal carbides.•Overview of selective oxygen removal ability of transition metal carbides from bio-oil derivatives.•Need to develop novel bimetallic carbides to avoid excessive hydrogen consumption.