One-pot Synthesis of High Value-added Chemicals from Furfural over Bimetal-doped Beta Zeolite and Carbon Solid Acid Catalysts

A series of bimetal-doped beta zeolites were prepared via a simple post-synthesis strategy including dealumination and metal ion incorporation. The incorporation of ferromagnetic metals into lattice sites of Sn-beta was evidenced by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The high reduction temperature (1094 K) of cobalt in Co-Sn-beta zeolite, as determined by temperature programmed reduction (TPR), confirms that Co interacts strongly with the zeolite support, consistent with lattice tetrahedral (Td) coordination. Co-doped Sn-beta zeolite was found to be a promising Lewis acid catalyst together with a carbon solid acid for the conversion of furfural to isopropyl 4-oxovalerate (i-PL) and y-valerolactone (GVL). The highest total yield of 92.02% was obtained after reaction for 16 h at 160 degrees C, including 48.3% i-PL, 37.7% GVL, and 6.0% levulinic acid (LA). The catalysts could also be applied as robust catalysts in glucose conversion to 5-hydromethylfurfural. Zeolite catalysts designed and prepared by this strategy contain multiple metals, enhancing their flexibility and adjustability of function via changing the species and ratio of metals to derive optimized catalysts for specific reactions.