【Frontiers in HaiChuan Chemical Technology】Dalian Institute of Chemical Physics develops a two-stage \"armored\" integrated electrode for efficient hydrogen production via hydrogen sulfide decomposition

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The two-stage “armor” integrated electrode I developed enables the efficient decomposition of hydrogen sulfide for hydrogen production. Publication date: 2025-03-11. Recently, the research team led by Researcher Deng Dehui and Associate Researcher Cui Xiaoju from the Energy and Environmental Small Molecule Catalysis Research Center (Group 509) at our Institute’s Catalysis Foundation **Key Laboratory has made new progress in the research on electrocatalytic decomposition of hydrogen sulfide to produce hydrogen. The team developed an integrated electrode with a two-stage \"armor\" structure, enabling the efficient decomposition of hydrogen sulfide into hydrogen and elemental sulfur at industrial ampere-level current densities. This work provides new ideas for the resource utilization of hydrogen sulfide pollutants in industrial exhaust gases and the sustainable production of green hydrogen energy. Hydrogen sulfide is a common toxic gas that is widely present in natural gas, refineries, and chemical manufacturing processes. It not only harms the environment but is also corrosive to equipment. Although the traditional Claus process can convert hydrogen sulfide into elemental sulfur, it cannot recover hydrogen. In contrast, electrocatalytic decomposition technology can simultaneously eliminate hydrogen sulfide pollutants and produce green hydrogen under mild conditions. However, the acidic corrosiveness of hydrogen sulfide causes the catalytic active centers made of non-precious metals to become easily deactivated during anodization reactions, and the electrode framework is also prone to structural collapse, making it difficult to achieve a balance between the catalyst’s activity and stability. This issue is particularly prominent under industrial-scale conditions with high current densities. Therefore, it is of great scientific significance and practical value to develop electrode materials that possess high catalytic activity, excellent structural stability, and are easy to produce on a large scale, in order to achieve high-throughput electrocatalytic decomposition of hydrogen sulfide for hydrogen production. The Dundee team has long been dedicated to the study of surface engineering of two-dimensional materials and their application in the catalytic conversion of small molecules for energy and environmental purposes. They introduced the concept of \"armored catalysis\" on the international stage, and have carried out systematic research on the structural design of such \"armored\" catalysts as well as the regulation of their catalytic properties (Angew. Chem. Int. Ed., 2013) ； Angew. Chem. Int. Ed., 2014 ； Nat. Nanotechnol., 2016 ； Adv. Mater., 2017 ； Adv. Mater., 2019 ； Nat. Commun., 2021 ； Angew. Chem. Int. Ed., 2024). Earlier, the team used graphene to encapsulate cobalt-nickel alloy nanoparticle catalysts, thereby demonstrating the feasibility and advantages of these \"armored\" catalysts in electrocatalytic systems for hydrogen sulfide decomposition (Energy Environ. Sci., 2020) ； The Innovation, 2021 ； EES Catal., 2023). On this basis, the team further developed a two-stage \"armored\" integrated electrode with a graphene-coated nickel foam skeleton; the first-stage \"armored\" structure consists of a nickel foam skeleton covered with graphene, while the second-stage \"armored\" structure is formed by graphene encapsulating metal nickel nanoparticles. This unique two-stage \"armor\" structure not only fully utilizes the protective effect of graphene encapsulation for the active sites, but also further enhances the catalytic activity on the surface of the graphene armor through the electronic regulation of graphene by the metal centers. Furthermore, this structure significantly enhances the chemical stability of the integrated electrode, thereby achieving an improvement in both catalytic activity and stability in the electrocatalytic decomposition of hydrogen sulfide. At a potential of 1.12 V vs. RHE, the anodic oxidation current density of this two-stage \"armored\" monolithic electrode can reach 1 A/cm², which is about 5 times that of nickel foam ； It can also operate stably for over 300 hours at a current density of 100 mA/cm², with a service life that is more than 10 times that of nickel foam, demonstrating excellent potential for industrial applications. In experiments simulating natural gas desulfurization, this two-stage \"armored\" monolithic electrode was able to achieve complete oxidation and removal of 20% hydrogen sulfide concentration at the anode, yielding elemental sulfur while producing high-purity hydrogen at the cathode. When the current density of the system reaches 200 mA/cm², its hydrogen production energy consumption is reduced by 43% compared to conventional water electrolysis processes, providing an efficient and low-energy alternative for natural gas purification and green hydrogen production. The relevant research findings were published recently in Angewandte Chemie International Edition under the title “Highly effective and durable integrated-chainmail electrode for H2 production through H2S electrolysis”, and were selected as a VIP (Very Important Paper) article. The above work was supported by projects such as the **Key Research and Development Program**, the basic science center project on \"Chemistry of Air Component Transformation\" funded by the National Natural Science Foundation of China, and the Class B pilot project of the Chinese Academy of Sciences titled \"Principles and Measurements for the Precise Construction of Functional Nanosystems».