Catalytic production of γ-valerolactone from xylose over delaminated Zr-Al-SCM-1 zeolite via a cascade process

A series of delaminated MWW-type Zr-Al-SCM-1 zeolites with large external surface area have been synthesized through a post-synthesized method by partial dealumination of SCM-1 and Zr incorporation based on parent SCM-1 zeolite, and used in the conversion of furfural and xylose to γ-valerolactone (GVL). The characterization of catalysts using XRD, FTIR, 29Si NMR, Raman, UV–vis and XPS spectroscopy confirmed the preservation of the parent SCM-1 zeolite network as well as the incorporation of Zr atoms into the zeolite framework with tetrahedral coordination. NH3-TPD and Py-FTIR spectroscopy reveal that the Zr-Al-SCM-1 zeolites possess both Brønsted and Lewis acid sites. When they are applied to the one-pot cascade conversion of furfural, a remarkable GVL yield of 47.3% with 85.6% carbon balance is obtained at 170 °C after 28 h. When considering xylose as starting substrate, up to 36.4% yield of GVL is achieved over Zr-Al-SCM-1 zeolites with excellent recyclability at 170 °C after 48 h. Moreover, the catalyst shows far superior catalytic performance and stability compared to the commercial MCM-22 based zeolites (Zr-Al-MCM-22).