美国北卡罗来纳大学Miller, Alexander J. M.团队报道了催化剂自组装加速双金属光催化氢在水中的析出。相关研究成果于2024年3月25日发表在《自然—化学》。

析氢是一种重要的燃料生成反应，它一直受到关于单金属和双金属途径作用的机制争论。

该研究中的分子铱催化剂通过双分子机制进行光电化学双氢（H₂）析出，为了解促进双金属H–H偶联的因素提供了机会。共价连接的二铱催化剂比单金属催化剂更快地从中性水中释放H₂，即使在较低的过电位下也是如此。

这种改进的意外起源于非共价超分子自组装成纳米级聚集体，有效地获取光并形成H–H键。含有长链烷烃取代基的单金属催化剂，利用自组装在低过电位下从中性水中释放H₂，其速率接近这种光驱动的水分解反应的预期最大值。

该项工作产生了将多个催化位点保持在附近，并调节催化剂微环境的设计参数。

附：英文原文

Title: Catalyst self-assembly accelerates bimetallic light-driven electrocatalytic H2 evolution in water

Author: Cloward, Isaac N., Liu, Tianfei, Rose, Jamie, Jurado, Tamara, Bonn, Annabell G., Chambers, Matthew B., Pitman, Catherine L., ter Horst, Marc A., Miller, Alexander J. M.

Issue&Volume: 2024-03-25

Abstract: Hydrogen evolution is an important fuel-generating reaction that has been subject to mechanistic debate about the roles of monometallic and bimetallic pathways. The molecular iridium catalysts in this study undergo photoelectrochemical dihydrogen (H2) evolution via a bimolecular mechanism, providing an opportunity to understand the factors that promote bimetallic H–H coupling. Covalently tethered diiridium catalysts evolve H2 from neutral water faster than monometallic catalysts, even at lower overpotential. The unexpected origin of this improvement is non-covalent supramolecular self-assembly into nanoscale aggregates that efficiently harvest light and form H–H bonds. Monometallic catalysts containing long-chain alkane substituents leverage the self-assembly to evolve H2 from neutral water at low overpotential and with rates close to the expected maximum for this light-driven water splitting reaction. Design parameters for holding multiple catalytic sites in close proximity and tuning catalyst microenvironments emerge from this work.

DOI: 10.1038/s41557-024-01483-3

Source: https://www.nature.com/articles/s41557-024-01483-3