The Pd-based catalysts have been widely studied for the combustion of volatile organic compounds, in which the roles of the Pd and the support are still not known clearly. In this study, mesoporous Co₃O₄ and CoO (i.e., meso-Co₃O₄ and meso-CoO) were prepared and used as support for the loading of Pd nanoparticles (NPs). The supported Pd samples performed much better than the supports for o-xylene combustion, in which the Pd/meso-CoO sample showed the best catalytic activity (T_90% = 173 °C), giving rise to reaction rates at 170 °C 3.5 and 84 times higher than those over the Pd/meso-Co₃O₄ and meso-CoO samples, respectively. It has been established that the meso-CoO sample possessed strong ability to activate oxygen molecules to the active oxygen species, the loaded Pd NPs in a metallic Pd phase was beneficial for o-xylene adsorption, and the adsorbed o-xylene species could immediately react with the active oxygen species at the interface between Pd NPs and meso-CoO. Therefore, we conclude that the excellent catalytic performance of the Pd/meso-CoO sample was associated with its highly active Pd–CoO interface.

中文翻译：

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CoO负载的介孔钯纳米催化剂对邻二甲苯的燃烧性能优异†

钯基催化剂已被广泛研究用于挥发性有机化合物的燃烧，其中钯和载体的作用仍不清楚。在这项研究中，中孔钴₃ ö ₄和CoO（即，内消旋-钴₃ ö ₄和内消旋- COO）制备并用作钯纳米颗粒（NP）的装载支持。负载的Pd样品的性能要好于邻二甲苯燃烧的载体，其中Pd / meso-CoO样品显示出最佳的催化活性（T _90％ = 173°C），从而在170°C时反应速率提高了3.5是Pd / meso-Co ₃ O _4的84倍和Meso-CoO样品。已经确定，介观CoO样品具有将氧分子活化成活性氧种类的强大能力，金属Pd相中负载的Pd NPs对邻二甲苯的吸附是有益的，并且所吸附的邻二甲苯物质可以立即反应。在Pd NP和内消旋CoO之间的界面处带有活性氧。因此，我们得出结论，Pd / meso-CoO样品的出色催化性能与其高活性的Pd-CoO界面有关。