Cerium sulfate doped ZrO2 as a solid acid catalyst for the synthesis of polyoxymethylene dimethyl ethers: Influence of Brønsted acidity on the catalytic activity and product selectivity

Abstract

Cerium sulfate doped ZrO2 solid acid catalyst was prepared by a simple wet impregnation method and tested its efficiency for the synthesis of polyoxymethylene dimethyl ethers (PODE). The surface Brønsted acidity contributed significantly for improved selectivity of desired PODE3–5 and higher PODEn>5. The overall acidity of the catalyst was directly related to the dispersion of CeO2 and the sulfate moiety. The polymerization of dimethoxymethane (DMM) and 1, 3, 5-trioxane (TOX) is in direct correlation with the surface Brønsted acid sites present on the cerium sulfate doped zirconia catalyst surface. The recovered catalyst showed consistent activity up to four catalytic cycles. The structural properties of the catalyst were rationalized by using p-XRD, BET-surface area, NH3-TPD, TGA, UV-DRS, IR, pyridine adsorbed IR, XPS and SEM analyses.