The transformation of methane into high-value products through catalytic conversion is a vital process. However, achieving both high activity and selectivity remains a significant challenge. Herein, we present a Ni(OH)₂-PMA catalyst, synthesized using solvothermal methods, for direct oxidation of methane to C1 oxygenates. This catalyst demonstrates remarkable activity in methane conversion. ¹H NMR results indicate that almost all liquid-phase products are the desired C1 oxygenates. When H₂O₂ is used as the oxidant, the catalyst achieves a C1 oxygenate yield of 6.77 mmol·g_cat^–1·h^–1 within 30 min at 80 °C, with an impressive selectivity of 98.44%. The catalyst shows excellent stability, maintaining activity over five cycles. The integration process of PMA with Ni(OH)₂ is revealed by characterization to produce abundant Ni-O active sites and oxygen vacancy, synergistically enhancing the ability of H₂O₂ decomposition into reactive oxygen species (•OH/•OOH) and simultaneously promoting the C-H activation of CH₄. Radical trapping experiments and mechanistic studies clarify the pathway of the reaction.

中文翻译：

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氢氧化镍多金属氧酸盐复合催化剂，用于甲烷高效直接氧化为 C1 含氧化合物

通过催化转化将甲烷转化为高价值产品是一个至关重要的过程。然而，同时实现高活性和选择性仍然是一个重大挑战。在此，我们提出了一种使用溶剂热法合成的 Ni（OH）2-PMA 催化剂，用于将甲烷直接氧化为 C1 含氧化合物。该催化剂在甲烷转化中表现出显著的活性。¹H NMR 结果表明，几乎所有液相产物都是所需的 C1 含氧化合物。当 H₂O₂ 作为氧化剂时，催化剂在 80 °C 下 30 分钟内达到 6.77 mmol·g cat–1·h–1 的 C1 含氧化合物产率为 6.77 mmol·g_cat^–1·h^–1，选择性高达 98.44%。该催化剂表现出优异的稳定性，可在五个循环中保持活性。通过表征揭示 PMA 与 Ni（OH）₂ 的整合过程，产生丰富的 Ni-O 活性位点和氧空位，协同增强 H₂O₂ 分解为活性氧 （•OH/•OOH） 的能力，同时促进 CH₄ 的 C-H 活化。自由基捕获实验和机理研究阐明了反应的途径。