Electroreductive upgradation of biomass into high-value chemicals and energy-intensive biofuels

Abstract

Biomass has always been regarded as a latent resource owing to the lack of competitive technology to convert it into an active substance. Electroreduction is considered as a burgeoning catalytic technology for upgrading biomass into a variety of high-value chemicals and energy-intensive biofuels through different transformation routes, such as hydrogenation, hydrogenolysis, deoxidation, reductive amination, and dimerization. This review summarizes recent advances in the electrocatalytic reduction of various biomass-derived molecules (e.g., levulinic acid, 5-hydroxymethylfurfural, furfural, phenol, guaiacol, benzaldehyde, acetophenone, and benzoic acid) by taking into account the particle size, morphology, and electronic structure of the catalysts as well as the applied potential, charge transfer, and acid/alkali balance of electrochemical cells. Insights into the reaction mechanisms and pathways are presented to formulate electrolytes and catalytic sites required for specific reactions. Another objective is to summarize and discuss documented catalyst modification strategies for enhancing the electrocatalytic reaction rate and selectivity. Present challenges, promising applications, and future orientations are also proposed.