Chinese scientists have uncovered a previously unknown atomic structure that could improve the efficiency of converting methane into useful industrial chemicals, potentially leading to more cost-effective catalysts. The discovery was made by researchers at the Dalian Institute of Chemical Physics (DICP), part of the Chinese Academy of Sciences (CAS). Their work focuses on partial oxidation of methane (POM), a method used to produce syngas—a mixture of carbon monoxide and hydrogen that is a key ingredient in various chemical processes. Previously, it was believed that tiny particles of metallic nickel (Ni) were the main active components in POM reactions. However, a new study published in the journal Nature Catalysis challenges this view. It suggests that the metallic nickel observed after the reaction might actually form due to the high-temperature reduction of nickel oxide by syngas, rather than being the original catalyst. This finding could shift the understanding of how these reactions work at a fundamental level. The research team, led by Prof. Tao Zhang, Aiqin Wang, and Xiaoyan Liu from DICP, developed a catalyst with a very low nickel content—just 0.8 weight percent—using a method called microemulsion. Despite this low concentration, the catalyst performed exceptionally well in POM, converting 92% of the methane into syngas with high selectivity for carbon monoxide and hydrogen. It also maintained a stable ratio of hydrogen to carbon monoxide, which is crucial for industrial applications. Further analysis showed that the metallic nickel nanoparticles present at the start of the reaction quickly transformed into nickel oxide (NiO) under POM conditions. However, pure NiO catalysts were inactive for POM and instead caused the complete combustion of methane. This contrast highlights the importance of the specific atomic structure that forms during the reaction. The study identified the in situ formation of a unique [Ni1O4Ni4] structural unit on the NiO(100) surface. This structure was found to significantly reduce the energy needed to break methane’s carbon-hydrogen bonds, a critical step in the reaction. Computational models confirmed that this structure has a much lower energy barrier for this process compared to traditional NiO or metallic nickel surfaces. The findings suggest that the catalytic activity comes from this newly identified atomic structure, which forms dynamically during the reaction, rather than from the metallic nickel or standard nickel oxide. This discovery emphasizes the importance of observing catalysts under real reaction conditions to understand their true active sites. It also opens new possibilities for designing more efficient catalysts that require less metal, potentially reducing costs and environmental impact in industrial processes.