Site‐Resolved Cu2O Catalysis in the Oxidation of CO.

The identification of the contribution of different surface sites to the catalytic activity of a catalyst nanoparticle is one of the most challenging issues in the fundamental studies of heterogeneous catalysis. We herein demonstrate an effective strategy of using a series of uniform cubic Cu2O nanocrystals with different sizes to identify the intrinsic activity and contributions of face and edge sites in the catalysis of CO oxidation by a combination of reaction kinetics analysis and DFT calculations. Cu2O nanocrystals undergo in situ surface oxidation forming CuO thin films during CO oxidation. As the average size of the cubic Cu2O nanocrystals decreases from 1029 nm to 34 nm, the dominant active sites contributing to the catalytic activity switch from face sites to edge sites. These results reveal the interplay between the intrinsic catalytic activity and the density of individual types of surface sites on a catalyst nanoparticle in determining their contributions to the catalytic activity. Choose your site: The dominant active site of CuO thin films on cubic Cu2O nanocrystals contributing to the catalytic oxidation of CO switches from face sites for large nanocrystals to edge sites for small ones. This reveals the interplay between the intrinsic catalytic activity and the density of individual types of surface sites on a catalyst nanoparticle. [ABSTRACT FROM AUTHOR]