Chinese scientists have found a hidden atomic structure that forms on nickel oxide during methane conversion, and it outperforms the metallic nickel long believed to drive the reaction. The discovery allowed a low-nickel catalyst to rival one containing 10 times more metal, potentially opening the door to cheaper and more efficient industrial catalysts.
The research, published in Nature Catalysis, was led by Profs. Tao Zhang, Aiqin Wang and Xiaoyan Liu from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, together with Prof. Wei Liu from DICP, Prof. Tao Yang from Xi’an Jiaotong University, and Prof. Graham J. Hutchings from Cardiff University.
The Problem With Metallic Nickel
Partial oxidation of methane (POM) is considered a promising industrial method for producing syngas, a mixture commonly used to make fuels and chemicals. For years, scientists have assumed that metallic nickel (Ni) nanoparticles serve as the main active centers that drive this reaction.
There has been an important unresolved question. The metallic Ni observed after a reaction may simply form when nickel oxide is reduced by syngas at high temperatures, rather than representing the species that actually performs the catalysis.
Nickel can change both its oxidation state and its atomic arrangement under the high-temperature redox conditions involved in POM. Until now, these changes have been difficult to track in detail, making it challenging to determine the true structure responsible for the reaction.
A Hidden Structure Forms During the Reaction
In the recent study, researchers found that highly active structures can form in situ when the surface of NiO reconstructs during POM. The results reveal the atomic-scale source of the catalytic activity and show why it is important to observe catalysts while they are operating under realistic reaction conditions.
To investigate the process, the team created a Ni/Al2O3 catalyst containing only 0.8 wt% Ni using a microemulsion method. Despite its relatively low nickel content, the catalyst performed strongly during POM. It converted 92% of the methane, while CO and H2 selectivities reached 87.0%, with the H2/CO molar ratio remaining stable at about 2.0.
High Performance With Much Less Nickel
One of the most striking findings was that almost no metallic Ni could be detected in the catalyst after the reaction. Even so, its overall performance was comparable to that of an 8.0 wt% Ni/Al2O3 catalyst produced through impregnation, despite containing only one tenth as much nickel.
The low-loading catalyst also performed far better than another 0.8 wt% Ni/Al2O3 material prepared using the same impregnation method. Under identical conditions, that catalyst did not effectively carry out POM and instead showed only methane combustion activity.
The researchers also observed that metallic Ni nanoparticles present at the beginning of the reaction were quickly oxidized into the NiO phase under POM conditions. Yet NiO alone was not enough. A pre-formed pure-phase NiO catalyst showed no POM activity and instead catalyzed only the complete oxidation of methane.
Atomic Reconstruction Reveals the True Active Site
A closer examination revealed what was actually happening on the catalyst surface. During the reaction, the researchers captured the in situ formation of a reconstructed [Ni1O4Ni4] structural unit on the NiO(100) surface.
DFT calculations indicated that this newly formed motif makes it much easier to break the C-H bonds in methane, one of the key steps in activating the molecule. The calculated activation barrier was only 12.5 kcal·mol-1.
That barrier was far lower than the value calculated for the intact NiO(100) surface (38.5 kcal·mol-1) and also below the barrier for the metallic Ni(111) surface (15.7 kcal·mol-1). This substantial kinetic advantage strongly supports the conclusion that the reconstructed structure is the true active center responsible for POM.
What the Numbers Show
The team’s findings rest on a direct comparison of three structures:
- The reconstructed [Ni1O4Ni4] unit: 12.5 kcal·mol-1 activation barrier
- The intact NiO(100) surface: 38.5 kcal·mol-1 activation barrier
- The metallic Ni(111) surface: 15.7 kcal·mol-1 activation barrier
The reconstructed structure wins on every count. It breaks methane’s C-H bonds far more easily than either the plain oxide or the metallic nickel that researchers had assumed was doing the work.
The Broader Lesson
“Our study highlights the critical role of in situ characterization in identifying dynamic active structures under reaction conditions,” said Prof. Liu.
The active site appeared only while the reaction was running. The source notes that almost no metallic Ni was detected in the catalyst after the reaction, and the reconstructed motif was captured in situ during POM.
The Study’s Authors and Methods
The paper, “In situ generation of active motifs on Ni/Al2O3 during partial oxidation of methane to syngas,” appears in Nature Catalysis, 2026; 9 (8): 848. The DOI is 10.1038/s41929-026-01580-1.
The authors are Yuanlong Tan, Qiao Zhao, Chen Liang, Chaobin Zeng, Hongwen Guo, Fengyuan Liu, Guang Xian Pei, James Hayward, Jingyuan Ma, Han Zhao, Xiao Yan Liu, Wei Liu, Tao Yang, Aiqin Wang, Graham J. Hutchings, and Tao Zhang.
Together, the experimental observations and theoretical calculations show that catalytic activity does not come simply from metallic nickel or ordinary nickel oxide. Instead, it emerges from a specific atomic structure that forms dynamically while the reaction is taking place.
“Dynamic reconstruction enables low-loading catalysts to achieve high performance, offering new opportunities for the rational design of efficient catalysts while reducing reliance on high metal loadings,” said Prof. Liu.
Materials were provided by the Dalian Institute of Chemical Physics, Chinese Academy of Sciences. The story was originally published on September 9, 2026.
Source: sciencedaily.com