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Adsorption and Reaction of C2H4 and O2 on a Nanosized Gold Cluster: A Computational Study
journal contribution
posted on 2015-08-06, 00:00 authored by Chen-Chi Lee, Hsin-Tsung ChenWe
have investigated the adsorption and reaction mechanisms of
C2H4 and O2 catalyzed by a Au38 nanoparticle based on periodic density-functional theory
(DFT) calculations. The configurations of the adsorption of C2H4/Au38, O2/Au38, and O/Au38 as well as the coadsorption of C2H4–O2/Au38 were predicted.
The calculation results show that C2H4, O2, and O are preferably bound at top (T), bridge (B), and hexagonal
(h) sites with adsorption energies of −0.66, −0.99,
and −3.93 eV, respectively. The detailed reaction mechanisms
for ethylene epoxidation on the Au38 nanoparticle has been
illustrated using the nudged elastic band (NEB) method. The oxidation
process takes place via the Langmuir–Hinshelwood (LH) mechanism
to generate ethylene oxide and acetaldehyde. The overall reaction
of C2H4 + O2 + Au38 →
ethylene oxide + O/Au38 is exothermic by 2.20–2.40
eV whereas those are 3.03–3.08 eV for the production of acetaldehyde
and O/Au38. The nature of the interaction between the adsorbate
and gold nanocluster has been analyzed by the detailed electronic
local density of states (LDOS) to understand the high catalytic activity
of the gold nanoclusters.