Design of active and stable Co-Mo-Sx chalcogels as pH-universal catalysts for the hydrogen evolution reaction
Design of active and stable Co-Mo-Sx chalcogels as pH-universal catalysts for the hydrogen evolution reaction
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DOI：
10.1038/nmat4481
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发表时间：
2016-02-01
期刊：
影响因子：
41.2
通讯作者：
Markovic, Nenad M.
中科院分区：
文献类型：
--
作者：
Staszak-Jirkovsky, Jakub;Malliakas, Christos D.;Markovic, Nenad M.
几十年来困扰电化学制氢的三个基本催化限制仍然存在：效率低、催化剂寿命短以及缺乏低成本材料。在这里，我们通过建立和探索结晶（CoS2和MoS2）和非晶（CoSx和MoSx）析氢催化剂的反应性和稳定性之间的密切功能联系来解决这三个挑战。我们建议 Co2+ 和 Mo4+ 中心促进水（碱性溶液）或水合氢离子（酸性溶液）的初始排放。我们发现，尽管 CoSx 材料比 MoSx 更活跃，但它们的稳定性也较差，这表明活性位点是 Co 和 Mo 阳离子溶解后形成的缺陷。通过将 CoSx 结构单元的较高活性与 MoSx 单元的较高稳定性结合到紧凑而坚固的 CoMoSx 硫族凝胶结构中，我们能够设计出贵金属催化剂的低成本替代品，用于在碱性和酸性环境中高效电催化生产氢气。
Three of the fundamental catalytic limitations that have plagued the electrochemical production of hydrogen for decades still remain: low effciency, short lifetime of catalysts and a lack of low-cost materials. Here, we address these three challenges by establishing and exploring an intimate functional link between the reactivity and stability of crystalline (CoS2 and MoS2) and amorphous (CoSx and MoSx) hydrogen evolution catalysts. We propose that Co2+ and Mo4+ centres promote the initial discharge of water (alkaline solutions) or hydronium ions (acid solutions). We establish that although CoSx materials are more active than MoSx they are also less stable, suggesting that the active sites are defects formed after dissolution of Co and Mo cations. By combining the higher activity of CoSx building blocks with the higher stability of MoSx units into a compact and robust CoMoSx chalcogel structure, we are able to design a low-cost alternative to noble metal catalysts for efficient electrocatalytic production of hydrogen in both alkaline and acidic environments.