Nitrogen-rich supports guide cobalt catalyst to convert CO2 into methanol

Using renewable electricity to convert carbon dioxide into fuels and chemicals is regarded as a promising route toward carbon-neutral energy systems. Among various CO₂ reduction products, methanol is particularly attractive because it is a liquid fuel with high energy density and broad industrial value. However, selective electrochemical conversion of CO₂ to methanol remains challenging, since the reaction involves multiple proton-coupled electron-transfer steps and competing pathways often lead to carbon monoxide or hydrogen instead.

Recently, a research team led by Prof. Baomin Xu from Southern University of Science and Technology, Prof. Zhongwei Chen from Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and Prof. Panagiotis Tsiakaras from University of Thessaly reported a strategy to tune a molecular cobalt catalyst for selective CO₂-to-methanol conversion. Their work was published in Chinese Journal of Catalysis. The researchers designed a series of composite catalysts by supporting cobalt phthalocyanine (CoPc) on nitrogen-containing materials, including N-MXene, TiN, and C₃N₄, to regulate the electronic structure around the cobalt active center.

The design principle is straightforward but effective. Instead of directly modifying the molecular catalyst itself, the team used nitrogen-rich supports to alter the local coordination and electron distribution of the cobalt center. This support-engineering approach created catalysts with markedly different product selectivity in CO₂ electroreduction. The results showed that nitrogen-containing supports were essential for steering the reaction beyond carbon monoxide and toward methanol.

Among the tested materials, CoPc/TiN delivered the best performance. In CO₂-saturated 0.5 M KHCO₃ under neutral conditions, CoPc/TiN achieved a methanol Faradaic efficiency of 53.28% at −1.0 V versus the reversible hydrogen electrode, together with a methanol partial current density of 68.76 mA cm⁻². By contrast, the catalyst without nitrogen-assisted coordination mainly produced CO and did not show effective methanol formation. The CoPc/TiN catalyst also exhibited stable current density and product selectivity during long-term testing, indicating good catalytic durability.

To understand the origin of the improved selectivity, the researchers combined XPS, EXAFS, electrochemical measurements, and density functional theory calculations. Their results indicate that the nitrogen-containing supports establish a distinctive local “Co–N–N” interaction with CoPc. This interaction redistributes electrons around the cobalt center and promotes the hydrogenation of the ^*CO intermediate to ^*HCO, which is a key step in the pathway toward methanol formation.

Theoretical calculations further showed that nitrogen-containing supports lower the reaction barrier for ^*HCO formation, while the TiN-supported system gives the most favorable energetics among the catalysts studied. In other words, the support is not simply a passive platform for loading CoPc; it actively regulates the electronic environment of the catalytic center and changes the reaction pathway. This insight helps explain why CoPc/TiN outperformed CoPc/C₃N₄ and CoPc/(Si)N-MXene in methanol production.

This work provides a new strategy for designing efficient electrocatalysts for CO₂ reduction. By engineering the interaction between molecular catalysts and nitrogen-rich supports, the researchers demonstrated a practical way to tailor product selectivity toward a valuable liquid fuel. The findings may also inspire the development of other catalyst-support systems for multi-electron electrochemical transformations relevant to carbon utilization and sustainable energy conversion. The results were published in Chinese Journal of Catalysis (DOI: 10.1016/S1872-2067(26)64971-6)

About the journal

Chinese Journal of Catalysis is co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis. Chinese Journal of Catalysis ranks among the top six journals in Applied Chemistry with a current SCI impact factor of 17.7.

At Elsevier http://www.journals.elsevier.com/chinese-journal-of-catalysis

Manuscript submission https://mc03.manuscriptcentral.com/cjcatal