Efficient one-pot catalytic conversion of xylose to C4/C5 cyclic ethers over a ZrO2-modified Ni-Pd/H-β catalyst

Herein, one-pot chemocatalytic conversion of xylose to value-added C5/C4 cyclic ethers over a novel ZrO2-doped Ni-Pd catalyst supported on H-β zeolite was demonstrated. Optimized catalyst, namely, Ni2Pd0.5Zr1/H-β(25), achieved a high xylose transformation (>99%) with high selectivities toward 2-methyltetrahydrofuran (48.6%) and tetrahydropyran (20.2%) under mild reaction conditions (200 °C, 1.0 MPa H2, and 2 h). Systematic investigation of the physicochemical properties of the catalyst revealed that ZrO2 doping induced O vacancies, enhanced H2 activation, and improved metal dispersion, thereby promoting hydrogenation and hydrodeoxygenation. In situ diffuse reflectance infrared Fourier transform spectroscopy using furfural and furfuryl alcohol probes confirmed preferential adsorption geometries and electronic interactions at metal-ZrO2 interfaces. Time-resolved and feedstock variation studies further elucidated the reaction mechanism and highlighted the roles of key intermediates. The proposed catalyst exhibited excellent recyclability with only a minor decline in performance after multiple xylose conversion cycles. This study provides mechanistic insights and design principles for the development of efficient multifunctional catalysts for biomass valorization.