Abstract
Strong metal-support interactions (SMSIs) are important in heterogeneous catalysis to control stability, activity, and selectivity. Core-shell nanostructures as a unique SMSI system not only stabilize the metal nanoparticles in the core, but also offer tunable structural and electronic properties via their interaction with the support shell. The Au@NiOx core-shell system, for example, is the first commercial nanogold catalyst to produce bulk chemicals via the oxidative esterification of aldehydes. However, how the SMSI effect in Au@NiOx manifests on its oxidative esterification activity is unclear. Here we use a model of an Au13@(NiO)48 core-shell nanocatalyst to examine the Au-NiO interaction and the associated electronic and geometric factors in enabling the oxidation of a hemiacetal (an intermediate from a ready reaction between an aldehyde and an alcohol) to an ester. We found 1.27 (e−) electrons flowing from the NiO shell to the Au core, leading to a higher oxide state of Ni atoms and the stabilization of key intermediates on the NiO shell. More importantly, lower activation energy was found on the Au13@(NiO)48 catalyst than on the Au(111) and NiO(100) surfaces for the rate-limiting step. Microkinetic modeling confirmed the high activity of the Au13@(NiO)48 catalyst in ester production in the experimental temperature range. Our work demonstrates the unique geometric and electronic effects of the Au@NiOx core-shell nanostructure on the catalytic oxidative esterification of aldehydes.
Original language | English |
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Pages (from-to) | 1317-1325 |
Number of pages | 9 |
Journal | Nanoscale |
Volume | 17 |
Issue number | 3 |
DOIs | |
State | Published - Nov 27 2024 |
Funding
This work was sponsored by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Catalysis Science Program. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC02-05CH11231. SZ thanks the National Academic Infrastructure for Supercomputing in Sweden (NAISS) (allocation no. NAISS 2024/5-22 and NAISS 2024/6-130) in Link\u00F6ping, Sweden.