Highly efficient H 2 production from H 2 S via a robust graphene-encapsulated metal catalyst

• Published in: Energy & environmental science 2020-01, Vol.13 (1), p.119-126
• Main Authors: Zhang, Mo, Guan, Jing, Tu, Yunchuan, Chen, Shiming, Wang, Yong, Wang, Suheng, Yu, Liang, Ma, Chao, Deng, Dehui, Bao, Xinhe
• Format: Article
• Language: English
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/C9EE03231B

The electrocatalytic decomposition of the abundant and toxic H 2 S from industrial by-products is a promising energy conversion technology for H 2 production and simultaneously removing this environmental pollutant. However, the development of such a technology has been hindered by the lack of low-cost, efficient and robust electrocatalysts. Herein, we reported a remarkable graphene-encapsulated metal catalyst, i.e. , nitrogen-doped graphene encapsulating a non-precious CoNi nanoalloy as the anode for highly efficient electrocatalytic H 2 production from H 2 S. This optimized catalyst could drive the anode reaction at an onset potential of 0.25 V, which was 1.24 V lower than that required for the water oxidation reaction, and delivered almost twice current density than that of Pt/C. Meanwhile, it exhibited approximately 98% H 2 faradaic efficiency and maintained long-term durability for more than 500 h without any decay. The density functional theory calculations revealed that the CoNi and nitrogen dopants synergistically facilitated the formation of polysulfides on graphene's surfaces. Furthermore, a demo showed 1200 h stability for removing H 2 S impurities from industrial syngas to produce hydrogen by this graphene-encapsulated metal catalyst, demonstrating its great potential for hydrogen production toward sustainable energy applications.