Vapor Phase Cross Ketonization of Pivalic Acid with Acetic Acid to Prepare Pinacolone Over Mg-Zr Mixed Oxide Catalysts

摘要

A sequence of MgO-ZrO2 mixed oxides with varying their ratios were synthesized by adopting co-precipitation method. These catalysts characteristics were deduced from different spectroscopic methods and used for vapor phase cross-ketonization of pivalic acid with acetic acid to produce pinacolone at atmospheric pressure. The characterization results indicated that at a high ZrO2 molar ratio, MgxZr1-xO2-x mixed oxide phase is formed, and it accounted for the presence of strong basic sites. MgO-ZrO2 mixed oxides ketonization activity is superior to individual oxides and the overall activity mainly depended on their molar ratio, calcination temperature, and presence of mixed oxide phase. The basicity of the MgO-ZrO2 mixed oxide catalyst is responsible for the high conversion of pivalic acid. The ketonization reaction is carried under different reaction parameters and optimized conditions were established. The catalysts are showed stability during the time on stream analysis.