The catalytic activity of well-designed hollow spinel NiCoO_x catalysts synthesized using a facile hard template method was investigated. These materials demonstrated higher performance during toluene oxidation compared with NiO, Co₃O₄, and NiCoO_x nanosheets with 100% conversion at 250 °C. Hollow NiCoO_x nanospheres (h-NiCoO_x) were found to have numerous surface hydroxyl groups and large surface areas together with oxygen vacancies, all of which promoted the oxidation reaction. Varying amounts of Pd were loaded on h-NiCoO_x and the catalytic efficiency was further improved. A 2.0 wt % Pd/h-NiCoO_x sample exhibited the highest activity, achieving approximately 100% toluene conversion at 190 °C with a lower activation energy of 41.9 kJ mol^–1 compared with the pristine h-NiCoO_x (95.6 kJ mol^–1). These results demonstrate that such materials have potential applications in the mitigation of toluene pollution.

中文翻译：

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具有表面羟基和氧空位的Pd改性NiCoO _x空心纳米球的构建，可提高甲苯的催化氧化活性

研究了一种使用简便的硬模板法合成的设计良好的空心尖晶石NiCoO _x催化剂的催化活性。与NiO，Co ₃ O ₄和NiCoO _x纳米片相比，这些材料在甲苯氧化过程中表现出更高的性能，并在250°C时具有100％的转化率。发现中空的NiCoO _x纳米球（h-NiCoO _x）具有许多表面羟基和大表面积以及氧空位，所有这些都促进了氧化反应。各种Pd负载在h-NiCoO _x上，催化效率进一步提高。2.0 wt％Pd / h-NiCoO _x样品表现出最高的活性，与原始的h-NiCoO _x（95.6 kJ mol ^-1）相比，在190°C下达到约100％的甲苯转化率，活化能更低，为41.9 kJ mol ^-1。这些结果表明，这种材料在减轻甲苯污染方面具有潜在的应用。