Tailoring the nature of zirconium sites on support to maximize catalytic upgrading of furfural

The utilization of biomass or its derived platform compounds for producing chemicals and fuels necessitates the development of advanced nanocatalysts. In this study, zirconium (Zr) catalysts featuring highly dispersed active sites on carbon black and hierarchical BEA zeolite supports were investigated for the selective upgrading of furfural to furfuryl alcohol and its ether derivatives. Structural characterizations revealed that catalyst supports not only influences the structural properties of Zr species through metal (oxide)-support interactions but also facilitates the formation of synergistic effects between Zr sites and surface functionalities, ultimately determining the reaction pathways and catalytic performance. The weak-acid/strong-base assemblies containing tetragonal ZrO 2 on carbon support serve as the active sites for the selective Meerwein-Ponndorf-Verley (MPV) reaction of furfural to furfuryl alcohol. In the case of hierarchical BEA zeolite framework-stabilized Zr species, isolated Zr OH groups engage in hydrogen bonding with the Si OH of silanol nests, resulting in the formation of the ( Si O) 3 Zr OH···HO Si complex as the active Lewis acidic center for the tandem hydrogenation-etherification reaction. Zirconium sites in BEA zeolite exhibit over an order of magnitude higher activity than carbon-supported counterparts, owing to the unique coordination environment of isolated Zr species that enables hydrogen-bonding with hydroxyl groups inside the zeolite pores. The systematic optimization of heterogeneous catalysts in this study leads to markedly improved catalytic performance, thereby offering a clear framework for the rational development of high-performing catalytic processes.