Oxidative transformation of aldehydes to corresponding esters is a reaction of significant importance. Catalytic oxidative esterification (OE) of aldehydes and alcohols in the presence of heterogeneous catalysts is an attractive method for production of esters. Reaction can be carried out by Pd based catalysts [1] in which Pb, Ag, Te, Sn, Bi [2] or Sb are used as the promoters to improve performance of catalysts. We present a systematic study on effect of Pd cluster size and promoters in liquid phase OE of benzaldehyde (BA) into methyl benzoate (MB) under base-free conditions using O2 as oxidant. Structure sensitivity of the benzaldehyde OE reaction was shown over a series of non-promoted Pd/Al2O3 catalysts with different palladium dispersions. The effects of Bi or Sb loading on catalytic activity and product selectivity were also studied. While addition of Bi can significantly improve the MB selectivity, the presence of Sb appears to enhance the formation of lights (CO2) with concurrent low MB selectivity. The nature of the active sites on Pd-Bi bimetallic system was probed via varying the Bi loadings and/or the oxidation state of Bi and will be discussed in this presentation.

Catalytic oxidative esterification of aldehydes to esters with air over supported Pd catalysts promoted with Bi or Sb

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.