Crystal-plane effects on surface and catalytic properties of Cu2O nanocrystals for NO reduction by CO.

In this work, Cu 2 O rhombic dodecahedrons {1 1 0}, octahedrons {1 1 1} and cubes {1 0 0} were synthesized to study the crystal-plane effects on surfaces and catalytic properties in NO + CO reaction. TPR results demonstrated the reducibility was ranked by {1 1 0} > {1 1 1} > {1 0 0}. Interestingly, the activity order in NO + CO reaction was well consistent with the reducibility order. Moreover, the in-situ formed metallic Cu nanoparticles affected by Cu 2 O exposed crystal planes were found on surfaces during the process. In-situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) studies revealed that the Mars van Krevelen mechanism worked in this system and the adsorption/dissociation of NO was the key step. Dodecahedral Cu 2 O {1 1 0} with better reducibility was more sensitive to the NO + CO reaction, and the generated interface between Cu 0 and Cu 2 O{1 1 0} was beneficial to the effective decomposition of adsorbed NO species. This work provided the scientific basis over Cu-based catalysts. [ABSTRACT FROM AUTHOR]