CO2 reduction on Cu2O(110) Surface: A Combined Theoretical and Experimental Study

Wednesday, 4 October 2017: 15:10
National Harbor 6 (Gaylord National Resort and Convention Center)
L. Li, R. Zhang, Y. Wu, Y. Liu, I. McNulty (Center for Nanoscale Materials, Argonne National Laboratory), J. Vinson, E. Shirley (National Institute of Standards and Technology), J. R. Guest, and M. K. Y. Chan (Center for Nanoscale Materials, Argonne National Laboratory)
The rational design of novel catalysts for CO2 reduction has attracted considerable attention, owing to the increasing global fuel demand and greenhouse gas emission. Cu2O has been suggested to be thermodynamically capable of photocatalytically reducing CO2 to methanol.1 However, due to the inertness of CO2 molecules, it is relatively hard for CO2 to draw electrons from the catalyst and become reactive. Earlier studies have shown that the CO2 conversion rate is quite limited on stoichiometric, defect-free oxide surfaces due to the low catalytic activity; on the other hand, defected surfaces generally have higher activity and may provide better catalytic performance.2

In this work, we performed density functional theory (DFT) calculations to investigate the catalytic activity of Cu2O(110) surface, with a primary focus on the surface affinity of CO2 molecules. The preferred CO2 adsorption sites and configurations on both pristine and defected Cu2O(110) surfaces are determined, and the surface stoichiometry that favors CO2 adsorption is thus identified. Scanning tunneling microscopy (STM) images and X-ray Absorption Near-Edge Structures (XANES) of various adsorption configurations are also simulated within the first-principles framework. The results from this study demonstrate the importance of rational surface engineering of catalysts for effective CO2 conversion, and provide important insight into experiment design.

(1) Bendavid, L. I.; Carter, E. a. First-Principles Predictions of the Structure, Stability, and Photocatalytic Potential of Cu2O Surfaces. J. Phys. Chem. B 2013, 117 (49), 15750–15760.

(2) Liu, L.; Zhao, H.; Andino, J. M.; Li, Y. Photocatalytic CO2 Reduction with H2O on TiO2Nanocrystals: Comparison of Anatase, Rutile, and Brookite Polymorphs and Exploration of Surface Chemistry. ACS Catal. 2012, 2 (8), 1817–1828.