Dynamic behavior of molecular Pd-acetate trimers and dimers in heterogeneous vinyl acetate synthesis

Year: 2025

Type: article

Abstract: Vinyl acetate monomer (VAM) is a crucial intermediate in the production of various polymers. While molecular Pd-acetate trimers and dimers, such as Pd3(OAc)6 and K2Pd2(OAc)6, are known to form on potassium acetate (KOAc)-promoted PdAu catalysts during heterogeneous VAM synthesis, their mechanistic role remains unclear. Here, we study the dynamics of different Pd-acetate species by utilizing in situ and operando crystallographic and spectroscopic characterizations combined with computational modeling on monometallic Pd model catalysts. The promoter-free catalyst expectedly shows low catalytic activity and VAM selectivity, corresponding to the complete reduction of Pdn(OAc)2n species to form Pd0 and PdCx nanoparticles. Conversely, noticeable quantities of KnPd2(OAc)n+4 species remain on the KOAc-promoted catalyst, leading to smaller nanoparticle formation with 10 times the activity and double the selectivity for VAM. This study reveals that molecular Pd-acetate trimers and dimers are significant indicators of catalytic performance and highlights their structurally dynamic nature in heterogeneous vinyl acetate chemistry. Vinyl acetate is an important polymer building block, but the mechanisms governing its catalytic production are not well understood. This study shows that dynamic palladium-acetate clusters determine catalyst efficiency and selectivity in vinyl acetate synthesis.

Source: Nature Communications

DOI: 10.1038/s41467-025-66820-7

Authors: Hunter P. Jacobs, Welman C. Elias, Kimberly N. Heck, Shan Jiang, Justin J. Dodson, Christian Sandoval-Pauker, Alexandre C. Foucher, Byeong Jun Cha, Jacob H. Arredondo, Laiyuan Chen, Sean G. Mueller, Steven R. Alexander, Thomas P. Senftle, Jeffrey T. Miller, Michael S. Wong

Institutions: Oak Ridge National Laboratory, Rice University, Purdue University West Lafayette, Celanese (United States), Center for Nanophase Materials Sciences, Seoul National University of Science and Technology

Language: English

Topic: Organometallic Complex Synthesis and Catalysis

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $6,990

Funders: U.S. Department of Energy, Office of Science, American Chemical Society Petroleum Research Fund, Oak Ridge National Laboratory, Brookhaven National Laboratory, National Renewable Energy Laboratory

OpenAlex ID: W4417153571