Effect of Reduction Treatment on CO Oxidation with CeO₂ Nanorod‐Supported CuO_x Catalysts

Abstract

Understanding the correlation of thermal treatment with catalyst activity provides mechanistic information about how the catalysts can be activated or deactivated. In this paper, we report that a comparative study was conducted on CeO2 nanorod‐supported CuOx catalysts before and after reduction treatment to gain insight on the effects of the copper oxidation state and catalyst–support interfacial interactions on CO oxidation. X‐ray diffraction, Raman spectroscopy, hydrogen temperature‐programmed reduction (H2‐TPR), and transmission electron microscopy (TEM) were used in a comprehensive way to study the effects of CuOx (0≤x≤1) composition as well as their spatial distribution on CeO2 nanorods on the H2 consumption and CO oxidation of the catalysts. These techniques were then used to gain a better understanding of the correlation between the different copper species (α, β, and γ‐type CuOx) and the multiple reduction (H2 consumption) peaks, found in the H2‐TPR data during the first run and during in situ reduction and redox cycling experiments. Also concluded from this study is that an abundance of surface defects are found on CeO2 nanorods from high‐resolution TEM, which consequently may be critical to strong CuOx(0≤x≤1)–CeO2−x(0≤x≤0.5) interactions, therefore resulting in the improved low‐temperature catalytic activity.

Recent Advances on the Rational Design of Non-Precious Metal Oxide Catalysts Exemplified by CuOx/CeO2 Binary System: Implications of Size, Shape and Electronic Effects on Intrinsic Reactivity and Metal-Support Interactions

“…Besides the advances that can be induced by adjusting the size, shape and electronic state of MOs, special pretreatment protocols or activation procedures could be applied to further adjust the local surface chemistry of MOs (e.g., [200,201]). In particular, the local surface chemistry of the MOs can be further tailored by appropriate pretreatment protocols, including thermal or chemical pretreatment.…”

Metal–Organic Framework (MOF)‐Derived Carbon‐Mediated Interfacial Reaction for the Synthesis of CeO2−MnO2 Catalysts

“…Some reports in the literature have demonstrated that CeO 2 ‐based oxides are good catalysts for CO oxidation . Herein, CO conversion as a function of the reaction temperature for the catalysts is shown in the Figure .…”

“…[31] Some reports in the literatureh ave demonstrated that CeO 2based oxides are good catalysts for CO oxidation. [32][33][34] Herein, CO conversion as af unctiono ft he reaction temperature for the catalysts is shown in the Figure 7. The conversion of CO that reaches 50 %( T 50 )i su sed to evaluate the catalytic activity of the samples.…”

Influence of the Hydrothermal Parameters on the Physicochemical Characteristics of Cu−Ce Oxide Nanostructures

“…The strong band at ca. [37,53,55,68,69] Interestingly, the absence of Raman peaks (at ca. [59][60][61] According to several studies, this band appears at ca.…”

“…1174 cm À 1 are linked with the presence of oxygen vacancies and/or defects in the CeO 2 structure. [37,53,55,68,69] Interestingly, the absence of Raman peaks (at ca. 295 cm À 1 and ca.…”