Review on Metal–Acid Tandem Catalysis for Hydrogenative Rearrangement of Furfurals to C5 Cyclic Compounds

Abstract

Hydrogenative rearrangement of biomass-derived furfurals (furfural and 5-hydroxymethyl furfural) to C5 cyclic compounds (such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O-containing value-added chemicals thereby replacing the traditional petroleum-based approaches. The scope for developing efficient bifunctional catalysts and establishing mild reaction conditions for upgrading furfurals to cyclic compounds has stimulated immense deliberation in recent years. Extensive efforts have been made toward developing catalysts for multiple tandem conversions, including those with various metals and supports. In this scientific review, we aim to summarize the research progress on the synergistic effect of the metal–acid sites, including simple metal–supported acidic supports, adjacent metal acid sites–supported catalysts, and in situ H2-modified bifunctional catalysts. Distinctively, the catalytic performance, catalytic mechanism, and future challenges for the hydrogenative rearrangement are elaborated in detail. The methods highlighted in this review promote the development of C5 cyclic compound synthesis and provide insights to regulate bifunctional catalysis for other applications.