Mesoporous NiO nano-sheet catalysts have been successfully synthesized by hydrothermal method with polyethylene glycol (NiO-PEG) and polyvinyl pyrrolidone (NiO-PVP) as soft templates. Compared with NiO catalysts prepared with direct calcination and precipitation methods, both NiO-PEG and NiO-PVP possess a large amount of intraparticle and interparticle mesopores with different sizes, thus resulting in catalysts with much higher surface areas. As a consequence, a larger quantity of more mobile active oxygen species have been formed in these two catalysts. It is believed that the mesoporous structure, high surface area and the presence of more mobile oxygen species are the major factors improving the activity of the catalysts for CH₄ deep oxidation. The formation of too much Ni³⁺ cations, which is induced by the Ni²⁺ vacancies present in the NiO crystal matrix, is harmful to the activity. With the optimal tuning of the above factors, NiO-PEG displays the highest activity to the target reaction, which is even rival to 1 wt.% Pd/Al₂O₃ catalyst. In addition, this catalyst exhibits excellent reaction stability in the presence or absence of water vapour, and certain physical and thermal stability for the reaction. Indeed, the information provided in this work may give people some inspiration to develop catalysts without using noble metals for air emission control reactions.

以聚乙二醇（NiO-PEG）和聚乙烯吡咯烷酮（NiO-PVP）为软模板，通过水热法成功合成了介孔NiO纳米片状催化剂。与直接煅烧和沉淀法制得的NiO催化剂相比，NiO-PEG和NiO-PVP都具有大量不同尺寸的颗粒内和颗粒间介孔，因此得到的催化剂表面积要大得多。结果，在这两种催化剂中已经形成了大量的更多的可移动的活性氧。据信，介孔结构，高表面积和更多可移动的氧种类的存在是提高催化剂对CH ₄深度氧化的活性的主要因素。Ni ³⁺的形成过多由NiO晶体基质中存在的Ni ²⁺空位引起的阳离子对活性有害。通过上述因素的最佳调整，NiO-PEG对目标反应显示出最高的活性，甚至可以与1 wt％的Pd / Al ₂ O ₃催化剂相媲美。另外，该催化剂在存在或不存在水蒸气的情况下显示出优异的反应稳定性，并且对于反应具有一定的物理和热稳定性。确实，这项工作中提供的信息可能会给人们一些启发，以开发催化剂而无需使用贵金属进行空气排放控制反应。