One-pot synthesis of ZrMo-KIT-6 solid acid catalyst for solvent-free conversion of glycerol to solketal

A series of zirconium and molybdenum species incorporated into ordered mesoporous silicate KIT-6 (ZrMo-KIT-6) materials were designed and synthesized from a one-pot hydrothermal method. The influences of Zr and Mo contents and calcination temperature in ordered mesoporous structure and existing states of introduced Zr and Mo species were systematically researched by SXRD, N-2-physisorption, TEM, elemental mapping, TG-DSC, WXRD, Raman, UV and XPS techniques. The results indicated that Zr and Mo species were incorporated into the skeleton of material as designed and existed as a highly dispersed state when the content was below 7%. Also, the ZrMo-KIT-6 material had ordered mesostructure with excellent textural properties, and the ordered mesoporous pores and highly dispersed Zr and Mo species could be preserved even treated at 700 degrees C. The acidic properties of ZrMo-KIT-6 materials were tested by NH3-TPD and FT-IR spectra of adsorbed pyridine techniques. Owing to the excellent acidic property, the ZrMo-KIT-6 material was employed as a solid acid catalyst for acetalization of glycerol with acetone. The ZrMo-KIT-6(5-700) material showed optimal catalytic performance (conversion of glycerol was 85.8% and selectivity of solketal was 97.8%), and there was no obvious decline in catalytic performance even after five cycles.