Recently, a research team led by Prof. DENG Dehui from the
Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences and their collaborators achieved highly efficient H
2 production from electrocatalytic decomposition of H
2S via a robust graphene encapsulating metal catalyst.
The study, published in
Energy & Environmental Science, provides a promising way for eliminating pollutant hydrogen sulfide and producing green hydrogen energy.
Left: Electrocatalytic decomposition of H2S for H2 production via robust chainmail catalyst. Right: Comparison of sulfide oxidation reaction and oxygen evolution reaction polarization curves for catalyst. The difference value of two reactions’ onset potential is 1.24 V. (Image by ZHANG Mo and GAO Hehua)
Hydrogen sulfide (H2S) is a toxic by-product of oil and gas production released in enormous quantities, and it is also a potential source of an important green energy carrier, namely, hydrogen gas. The current industrial technology for removing H2S only recovers sulfur from H2S, while the hydrogen constituent is wasted as steam.
The electrocatalytic decomposition of H2S is a kind of mild and efficient method, which produces hydrogen at the cathode and recycles sulfur at the anode simultaneously. However, this technique is hindered by lacking suitable catalysts. Therefore, it's crucial to develop a low-cost, high-efficient and robust electrocatalyst.
Based on the concept of chainmail catalysts firstly proposed by DENG’s group, the researchers developed a kind of new graphene-encapsulated non-precious metal chainmail material as a low-cost and high activity electrocatalyst for decomposition of H2S.
The optimized catalyst drove hydrogen production from decomposing H2S at a much lower potential, which decreased 1.24 V than that of water splitting. Meanwhile, it displayed high activity which was almost twice current density than that of Pt/C, and maintained 500 h stability without decay.
Furthermore, they demonstrated that the superiority of catalyst originated from the modulation of the electronic structure of graphene surface by metal core and nitrogen dopant through the combination of theory and experiment results.
The study was supported by Ministry of Science and Technology of China, National Natural Science Foundation of China, Key Research Program of Frontier Sciences of the Chinese Academy of Sciences, the DNL Cooperation Fund and Collaborative Innovation Center of Chemistry for Energy Materials (2011. iChEM).
