【Frontiers in HaiChuan Chemical Technology】New progress achieved in research on electrocatalytic decomposition of hydrogen sulfide to produce hydrogen at the Dahuaxi Research Institute

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The team led by Researcher Deng Dehui and Associate Researcher Cui Xiaoju from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, has made new progress in the research on the electrocatalytic decomposition of hydrogen sulfide for hydrogen production. 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. Recently, the relevant findings were published in German Applied Chemistry. Hydrogen sulfide is a common toxic gas that is widely present in natural gas, refineries, and chemical 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 is unable to recover hydrogen gas. 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 can easily lead to the deactivation of the catalytic active centers made of non-precious metals during anodic oxidation reactions; moreover, the electrode framework is prone to structural collapse, making it difficult to achieve both the activity and stability of the catalyst. This problem 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. It introduced the concept of \"armored catalysis\" on the international stage, and has carried out systematic research on the structural design of such \"armored\" catalysts as well as the regulation of their catalytic properties. On this basis, the team further developed a two-stage “armored” integrated electrode with graphene-encapsulated nickel foam scaffolds. The primary “armor” structure of the electrode consists of a graphene-coated nickel foam skeleton, while the secondary “armor” structure is formed by graphene-encapsulated nickel metal nanoparticles. This unique two-stage \"armor\" structure not only fully utilizes the protective effect of graphene encapsulation on the active sites, but also further enhances the catalytic activity of the graphene \"armor\" surface 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. In simulated natural gas desulfurization experiments, this two-stage \"armored\" integrated electrode was capable of achieving complete oxidation and removal of hydrogen sulfide at a concentration of 20% at the anode, yielding elemental sulfur while producing high-purity hydrogen at the cathode. This study provides new insights for the resource utilization of hydrogen sulfide pollutants in industrial exhaust gases and the sustainable production of green hydrogen energy.