Effect of tungsten oxide on ceria nanorods to support copper species as CO oxidation catalysts

In this work, tungsten oxide with different concentrations (0, 0.4 at%, 2.0 at% and 3.2 at%) was introduced to the ceria nanorods via a deposition-precipitation (DP) approach, and copper species of ca. 10 at% were sequentially anchored onto the modified ceria support by a similar DP route. The aim of the study was to investigate the effect of the amount of tungsten oxide (0, 0.4 at%, 2.0 at%, and 3.2 at%) modifier on the copper-ceria catalysts for CO oxidation reaction and shed light on the structure-activity relationship. By the aids of multiple characterization techniques including N-2 adsorption, high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), and temperature-programmed reduction by hydrogen (H-2-TPR) in combination with the catalytic performance for CO oxidation reaction, it is found that the copper-ceria samples maintain the crystal structure of the fluoritefcc CeO2 phase with the same nanorod-like morphology with the introduction of tungsten oxide, while the textural properties (the surface area, pore volume and pore size) of ceria support and copper-ceria catalysts are changed, and the oxidation states of copper and tungsten are kept the same as Cu-2(+) and W-6(+) before and after the reaction, but the introduction of tungsten oxide (WO3) significantly changes the metal-support interaction (transfer the CuOx clusters to Cu-[O-x]-Ce species), which delivers to impair the catalytic activity of copper-ceria catalysts for CO oxidation reaction. (c) 2021 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Automated summary

This study investigated the effect of tungsten oxide on copper-ceria catalysts for CO oxidation reaction. The introduction of tungsten oxide changed the metal-support interaction and impaired the catalytic activity of copper-ceria catalysts for CO oxidation reaction. Various characterization techniques were used to analyze the structural and textural changes in the catalysts.