Understanding how the shape of a nanocatalyst alters its catalytic performance is essential for the design of active catalysts at the nanoscale. This report describes novel findings of an investigation of CuO/CeO₂ nanocatalysts with different shapes for preferential CO oxidation (CO-PROX), aiming at unraveling the structural origin of the high catalytic activity. CuO/CeO₂ catalysts with a series of shapes, including octahedron, rod, cube, sphere and spindle morphologies, were synthesized by a combination of hydrothermal and impregnation methods. By probing the structure, elementary valence and reductivity of the catalysts using an array of techniques, an intriguing structure-activity synergy is revealed, pinning the origin of the highest catalytic activity to the intersection of the nanocrystal planes. The CuO/CeO₂ catalysts with spheres and spindles featuring exposed {111} and {002} crystal planes of CeO₂ were found to exhibit the lowest reaction temperature in terms of 50% CO conversion and a wider temperature window for the complete CO conversion in CO-PROX. The catalytic synergy reflects a combination of high surface area, reduced state of copper sites, high oxygen vacancies, as well as stronger interaction between CuO and CeO₂. This synergy was further substantiated by analysis of the results based on DFT calculation, showing that the oxygen vacancies were the highest at the intersection of {111} and {002} facets, but the lowest on CeO₂ {111} surface. The finding of {111} and {002} facets with an increased oxygen vacancy and a stronger metal-support interaction for improving the catalytic performance has important implications for designing facet-tunable nanocatalysts for efficient PROX.

了解纳米催化剂的形状如何改变其催化性能对于纳米级活性催化剂的设计至关重要。这份报告描述了针对优先CO氧化（CO-PROX）的不同形状的CuO / CeO ₂纳米催化剂研究的新发现，旨在揭示高催化活性的结构来源。CuO / CeO ₂结合水热法和浸渍法合成了八面体，棒状，立方体，球形和纺锤形等一系列形状的催化剂。通过使用一系列技术探索催化剂的结构，元素价和还原性，揭示了一种有趣的结构活性协同作用，将最高催化活性的起源固定在了纳米晶平面的交点上。具有球形和纺锤形特征的CuO / CeO ₂催化剂，具有暴露的CeO _2的{111}和{002}晶面发现在50％的CO转化率方面，最低的反应温度和在CO-PROX中实现完全的CO转化率的温度范围更宽。催化协同作用反映了高表面积，铜位点状态减少，高氧空位以及CuO和CeO ₂之间更强的相互作用的组合。通过基于DFT计算的结果分析进一步证实了这种协同作用，结果表明，氧空位在{111}和{002}面相交处最高，而在CeO _2上最低{111}表面。发现{111}和{002}面具有增加的氧空位和更强的金属-载体相互作用以改善催化性能，这对于设计用于高效PROX的面可调纳米催化剂具有重要意义。