While palladium-based catalysts are effective in low-temperature methane combustion, their high cost and scarcity render them unsuitable to fulfil the growing demand. The design of improved catalysts which can more efficiently utilize this precious metal is required. Here, by using a facile one-pot thermal decomposition method Pd-NiCo₂O₄ spinel catalysts with a unique structure are obtained, in which the majority of Pd incorporated into the bulk spinel structure of NiCo₂O₄ with limited highly dispersed PdO_x species on the surface at an atomic scale. The robust 1 %Pd-NiCo₂O₄ spinel catalyst exhibits comparable activity in methane oxidation to that of the conventional incipient wetness impregnation 2 %Pd/NiCo₂O₄. Theoretical calculations and catalyst characterizations (SEM, HRTEM, XRD, XPS, XAS, ICP-OES, etc.) revealed that the enhanced activity is mainly originated from having the O p-band center closer to the Fermi level, with Pd ions incorporated into the bulk NiCo₂O₄ via substituting for the octahedral coordinated Ni³⁺/Co³⁺.

虽然钯基催化剂在低温甲烷燃烧方面很有效，但其高成本和稀缺性使其不适合满足不断增长的需求。需要设计可以更有效地利用这种贵金属的改进催化剂。在这里，通过使用简便的一锅热分解法，获得了具有独特结构的Pd-NiCo ₂ O ₄尖晶石催化剂，其中大部分 Pd 结合到 NiCo ₂ O ₄的本体尖晶石结构中，而高度分散的 PdO _x有限在原子尺度上的表面物种。坚固的 1 % Pd-NiCo ₂ O ₄尖晶石催化剂在甲烷氧化中表现出与传统初湿浸渍 2%Pd/NiCo ₂ O ₄相当的活性。理论计算和催化剂表征（SEM、HRTEM、XRD、XPS、XAS、ICP-OES 等）表明，增强的活性主要源于 O p 带中心更接近费米能级，Pd 离子掺入通过取代八面体配位Ni ³⁺ /Co ³⁺得到块体NiCo ₂ O ₄ 。