Metal phosphate catalysts to upgrade lignocellulose biomass into value-added chemicals and biofuels

Abstract

Alternative and green sources of energy are needed to replace rapidly depleting and non-renewable fossil fuels. Abundant and renewable lignocellulose biomass can be transformed into value-added chemicals and biofuels that are currently derived from non-renewable fossil fuels. The conversion of lignocellulose biomass has been extensively investigated over heterogeneous catalysts via various catalytic processes. In particular, solid acid catalysts possessing both Lewis and Brønsted acid sites have drawn significant research interest. Among these catalysts, metal phosphates are of particular interest due to their relatively facile synthesis routes, low cost, environmental friendliness, and tunable Lewis and Brønsted acid sites. In this tutorial review, we have provided a brief overview of the synthesis methodologies and have summarized several catalytic processes involved in biomass upgrading, including dehydration, oxidation, transfer hydrogenation, transesterification, hydrogenolysis, and hydrodeoxygenation over metal phosphate catalysts to produce value-added chemicals and biofuels. The main emphasis is to highlight the relationship between the textural properties of the catalysts and their catalytic performances and to elucidate future research opportunities available in this exciting area.