CeO2–ZrO2 Solid-Solution-Supported CuO Nanocatalysts for Efficient CO Oxidation

CuO/CeO2–ZrO2 catalysts have been extensively studied for CO oxidation due to their cost-effectiveness and high performance. However, catalysts synthesized by conventional methods often suffer from agglomeration, low oxygen vacancy content, and weak metal–support interactions, limiting their catalytic efficiency. In this study, the flame spray pyrolysis (FSP) technique was used to synthesize highly dispersed CuO on CeO2–ZrO2 solid solution supports. The optimal CuO loading of 2.0 wt % achieves high dispersion of CuO on the support, resulting in the highest CO oxidation performance among the investigated catalysts. This enhanced activity is attributed to increased surface oxygen, strong Ce–O–Cu bonding, and abundant oxygen vacancies. Additionally, the addition of a small amount of ZrO2 to the CeO2-based support further improves the catalyst activity by enhancing the number of oxygen vacancies and the oxygen storage capacity. Furthermore, the FSP-prepared catalyst exhibits higher catalytic performance and stability compared to those produced by the conventional incipient wetness impregnation method, highlighting the advantages of FSP in preparing catalysts with enhanced CO oxidation performance. This work demonstrates that FSP is a promising technique for synthesizing highly dispersed catalysts and oxygen-vacancy-rich supports to achieve exceptional catalytic performance.