Work

Disentangling the Catalytic Mechanisms of C 60 -Buffered Cu/SiO 2 Catalyst for DMO-to-EG Conversion

Year: 2024

Type: article

Abstract: Both ethylene glycol and methyl glycolate, which can be synthesized by hydrogenating dimethyl oxalate, are important chemical feedstocks, and understanding the mechanistic details underlying those hydrogenation reactions is of pivotal importance for the design of high-performance catalysts. In this work, we employ carefully constructed model cluster catalysts, including Cu 4, C 60 Cu, C 60 Cu 3, and C 60 Cu 4, to mimic the widely utilized Cu/SiO 2 catalyst and the recently discovered C 60 -buffered Cu/SiO 2 catalyst based on joint efforts from mass spectrometry, photoelectron spectroscopy, density functional theory calculations, and molecular dynamics simulations. We explored the catalytic mechanisms of the hydrogenation of dimethyl oxalate catalyzed by our model cluster catalysts and uncovered the possibility to tune the product selectively by changing the copper cluster size. Our results reveal important geometric and electronic effects of C 60 in promoting the catalytic reactions by reversibly accepting and donating, i.e., serving as an electron buffer, electrons to the adsorbed copper, resulting in the alternating formation of Cu 0 and Cu δ+ sites in different steps of the hydrogenation reactions. These oxidation state changes are crucial for the hydrogenation and stabilization of the reaction intermediates.

Source: ACS Catalysis

DOI: 10.1021/acscatal.4c03943