Produção catalítica do acetato de vinila a partir de fontes renováveis de etileno e ácido acético sobre catalisadores bimetálicos de Pd-Cu suportados em ZrO2 modificada

Abstract

The main objective of this work was the study of catalytic production of vinyl acetate monomer (VAM) in gas phase from ethylene, acetic acid, and oxygen; including the development of bimetallic catalysts containing palladium and copper over modified ZrO2. The focus was the study of mechanistic aspects of VAM formation by catalytic ethylene acetoxidation. The characterization results showed that characteristics of the geometric and the structural arrangement of catalysts influenced the catalytic activity. The results of catalytic tests were analyzed using a statistical approach from statistical analysis of experimental errors, with the aim of explain a reaction mechanisms based on a microkinetic analysis. Through XPS studies, it was possible to determine the oxidation state of Pd and Cu species involved in the reaction. In addition, the formation of Pd carbides wasn’t evidenced, indicating that Pd particles remain highly stable after reaction. From catalytic tests, XPS and DRIFTS results, a reaction mechanism was proposed; in which, the VAM formation depends on dehydrogenation on the active site and H2 spillover phenomena from Cu/ZrO2 interface.