Hydrogen sulfide (H2S), a toxic and corrosive byproduct of fossil fuel extraction, poses significant environmental and industrial challenges. While the conventional Claus process converts H2S into elemental sulfur, it fails to recover hydrogen gas, missing an opportunity for sustainable energy production.
Electrocatalytic H2S decomposition offers a promising alternative, simultaneously eliminating pollutants and producing green hydrogen under mild conditions. However, the acidic nature of H2S deactivates non-precious metal catalysts and degrades electrode structures, resulting in a challenge to achieve both high efficiency and long-term stability.
Efficient H2S electrolysis to H2 production in the flow-cell device using chainmail integrated-electrode (Image by ZHANG Mo)
In a study published in Angew. Chem. Int. Ed., a research group led by Prof. DENG Dehui and Assoc. Prof. CUI Xiaoju from the State Key Laboratory of Catalysis has developed a dual-level chainmail integrated-electrode that enables highly efficient hydrogen production via H2S electrolysis.
The researchers designed a graphene encapsulating nickel foam (Ni@NC foam) electrode with a dual-level chainmail structure, significantly enhancing both catalytic activity and durability. This electrode achieved an industrial-scale current density exceeding 1 A/cm2 at 1.12 V versus the reversible hydrogen electrode, which was five times higher than commercial nickel foam. Moreover, the Ni@NC foam remained stable for over 300 hours, demonstrating a lifespan at least ten times longer than commercial nickel foam electrodes.
In a simulated natural gas desulfurization test, the chainmail integrated-electrode completely oxidized and removed 20% H2S at the anode, simultaneously producing sulfur powder. Meanwhile, high-purity hydrogen was collected at the cathode. Compared to conventional water electrolysis, the system reduced energy consumption by 43% at the current density of 200 mA/cm², offering a more sustainable approach to hydrogen production.
"Our study provides an efficient, low-energy solution for natural gas purification and opens up the potential of converting H2S into valuable hydrogen fuel for industrial applications," said Prof. DENG.
