Carbonized Core-Shell Diatomite for Efficient Catalytic Furfural Production from Corn Cob

A novel core-shell sulfonated tin-loaded diatomite catalyst, namely SO42−/CX-DMSn, was synthesized by hybridizing sulfuric carbon layer on DM-Sn intermedium. Lewis and Brønsted acid sites displayed on the surface of DM core and on the coated carbon layer of the SO42−/CX-DMSn, respectively. The catalyst exhibited excellent catalytic ability, high water tolerance and good stability. The existence of acid sites and carbon layer on the diatomite were characterized by SEM, EDS, XRD, XPS, NH3-TPD and Py-IR. The unique core-shell structure of the carbonized diatomite catalyst significantly improved furfural production from xylose and lignocellulosic matrix even in organic solvent-free process. Results showed 66.24% of furfural yield and 79.92% of selectivity were obtained from xylose, whilst 65.74% of furfural yield and 66.83% of selectivity from corn cob, implying the side reactions for furfural production were well-eliminated. This strategy shows a promising application for novel SO42−/CX-DMSn material toward effective and green catalytic production of furfural from biomass materials.