DIMENSIONALLY STABLE ELECTRODES FOR SUPERCRITICAL WATER ELECTROLYSIS (SuperH2)

开发具有成本效益的绿色制氢系统是发展充满活力的低碳经济的最紧迫挑战之一。氢对英国净零排放路线图的影响在政府的2021年氢战略和绿色工业革命十点计划中有广泛描述。英国的目标是到2030年发展5吉瓦的低碳生产。为了实现这一目标，水电解制氢（绿色氢）发挥着核心作用。成熟的水电解技术，如碱性（AEC）和聚合物电解质膜（PEM）电解槽，目前正在作为与可再生能源发电相结合的储能系统进行规模化。然而，氢气压缩和关键原材料（如Pt和Ir）的可用性等方面对GW规模的运营提出了重要挑战。在高温和高压下操作电解槽，例如在固体氧化物电解槽（SOE）的情况下，在总体能量平衡和氢生成效率方面提供了显著的优点。然而，SOE是一种新兴技术，在制造高质量陶瓷膜系统的可扩展性方面也面临挑战。SuperH 2是布里斯托大学和位于伦敦的中小企业Supercritical Solutions Ltd之间的合作项目，旨在开发尺寸稳定的材料，用于超临界条件下的水电解。这些材料将是在超临界水流下工作的高度新颖的电解槽设计中的关键活性元素，从而在不存在膜的情况下通过浮力驱动分离H2和O2。这种独特的技术可以利用工业场所的废热，同时在220 bar以上的压力下产生H2。SuperH 2将检测用Pt、Fe和Co改性的Ni基材料在碱性溶液中从标准到超临界条件下的析氢反应（HER）的电催化活性。我们将利用掺硼金刚石（BDD）电极作为金属活性位点的尺寸稳定的支持。该项目将在标准和超临界条件下提供碱性电解质中HER的组成-活性相关性。在基础水平上，这些研究将揭示金属位点的水解离动力学，碱性条件下HER的关键限制步骤，如何受到温度和压力的影响。这些研究还将建立稳定性和活性之间的相关性，这是在超临界水电解槽中配制电极材料的关键。

The development of cost-effective green hydrogen-generation systems is one of the most pressing challenges towards the development of a vibrant low-carbon economy. The impact of hydrogen on the UK's roadmap to Net Zero is extensively described in the government's 2021 Hydrogen Strategy and the Ten-Point Plan for a Green Industrial Revolution. The UK aims to develop a 5 GW low-carbon production by 2030. Towards this target, hydrogen production by water electrolysis, green hydrogen, play a central role.Matured water electrolysis technologies such as alkaline (AEC) and polymer electrolyte membrane (PEM) electrolysers are currently being scaled up as energy-storage systems coupled to renewable-energy generation. However, aspects such as hydrogen compression and availability of key raw materials (e.g. Pt and Ir) pose important challenges towards operations at the GW scale. Operating electrolysers at high temperature and pressure, such as in the case of solid oxide electrolysers (SOE), offers substantial advantages with regards to the overall energy balance and hydrogen generation efficiency. However, SOE is an emerging technology which also faces challenges in scalability associated with manufacturing high-quality ceramic membrane systems.SuperH2 is a collaboration between University of Bristol and Supercritical Solutions Ltd, a SME based in London, aiming at the development of dimensionally stable materials for water electrolysis under supercritical conditions. These materials will be key active elements in a highly novel electrolyser design working under flow of supercritical water, leading to the separation of H2 and O2 driven by buoyancy, without the presence of a membrane. This unique technology can utilise waste heat from industrial sites, while generating H2 at pressures above 220 bar.SuperH2 will examine the electrocatalytic activity of Ni based materials, modified with Pt, Fe and Co, towards the hydrogen evolution reaction (HER) in alkaline solutions from standard to supercritical conditions. We will utilise boron-doped diamond (BDD) electrodes as dimensionally stable supports for the metallic active sites. The project will deliver a composition-activity correlation towards HER in alkaline electrolytes at standard and supercritical conditions. At the fundamental level, these studies will uncover how water dissociation dynamics at metallic sites, the key limiting step in HER under alkaline conditions, can be affected by temperature and pressure. These studies will also establish correlations between stability and activity, which is key for formulating electrode material in supercritical water electrolysers.