Copper-based oxides are widely used in heterogeneous catalysis, attracting studies into the atomistic mechanism over decades. On Cu(110), oxidation leads to the formation of Cu-O- chains in the 2x1 reconstruction over the entire surface, which in turn serves as a model CuO surface. While the pristine Cu(110)-2x1-O surface is generally considered to be unable to catalyze CO oxidation, there are rich examples in the literature that CO can be activated on metal-loaded Cu(110)-2x1-O surfaces, via Mars-van Krevelen (MvK) mechanism, in which a substrate oxygen is abstracted by CO. In the current work, we employed density functional theory simulations to study the CO oxidation reaction on Cu(110)-2x1-O surfaces doped by foreign species and compared our results with that on the pristine Cu(110)-2x1-O surface. The foreign species under our consideration include an oxygen vacancy and a series of anions (N3-, P3- and S2-). First, we studied the adsorption of CO in terms of geometry structure, electronic structure, and energetics. As against to that on the pristine Cu(110)-2x1-O surface where CO adopts both vertical (Eads= 0.38 eV) and titled (Eads = 0.61 eV) alignments, we find clear alteration in CO adsorption on doped Cu(110)-2x1-O surfaces; that is, titled CO adsorption is present in the absence of the vertical alignment, and the heats of adsorption of the titled CO are of 0.48, 0.87, 1.10 and 1.11 eV for the CO adsorption on N-, oxygen vacancy-, P- and S-doped Cu(110)-2x1-O surfaces. Analysis of the projected density of states and partial charge reveals the hybridization between the orbitals of CO and the 3d orbitals of the adsorbed Cu-atom, which is in agreement with the Blyholder model. Next, we pursue the CO oxidation reaction pathway via the MvK mechanism, using the climbing image nudged elastic band technique. Preliminary results were obtained on the pristine Cu(110)-2x1-O surface, which features a bent CO2 geometry for the transition state with a barrier of 0.64 eV. Comparative work on doped surfaces is underway, to provide further insights into the effect of doping on the atomistic mechanism of CO oxidation reaction.

Activation of CO oxidation on doped Cu(110)-2×1-O surfaces: A density functional theory study

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.