Conversion of bio-oil components with carbon chain elongation: advantages of bifunctional catalysts and tandem processes

Lignocellulosic bio-oil is a promising renewable feedstock the components of which can be converted to fuels and valuable petrochemicals. This review gives the first systematic summary of the modern strategies for the catalytic processing of bio-oil components in tandem and one-pot processes that combine the formation of new C–C bonds with hydrodeoxygenation/ hydrogenation. Particular attention is paid to bifunctional catalysts that have both acid/base and metal active sites. The key factors determining product yields and catalytic performance are analyzed, including the structural features of catalysts, the nature of substrates (furan derivatives, phenols, carbonyl compounds), and the composition of the reaction medium. The role of water, acting as both a solvent and a reactant, is highlighted for tandem and one-pot processes; the beneficial and adverse effects of water on bifunctional catalysts are considered. The review also compares the efficiency of conventional petrochemical methods and advanced electro- and photocatalytic approaches for the conversion of bio-oil components into hydrocarbons through C–C bond formation followed by hydrodeoxygenation. <br>The bibliography includes 183 references.