Electrolysis at scale: a pathway to lower precious metal content electrolysers

清洁和可持续的氢将对我们经济的几个部门的未来产生重大影响-从工业过程（例如钢铁和混凝土制造），家庭和工业供暖，到运输部门（例如燃料电池和内燃机），氢提供了许多脱碳途径。最近，英国政府的氢战略明确阐述了这一点。然而，为了使氢能够发挥其潜力，它必须由无碳排放的可再生能源生产。用电将水分解为氢和氧（电解）是应对这一挑战最有前途的技术之一。事实上，目前已经商业化的电解槽可以在工业相关规模上产生“绿色”氢。然而，迄今为止，96%的氢是由化石燃料衍生的过程产生的，导致碳排放。虽然从长远来看，一系列电解槽技术将发挥重要作用，但人们普遍预计质子交换膜电解槽（PEM-ELs）将在中短期内提供基本产能。尽管有这样的期望，但从PEM-EL中获得绿色氢的高成本是一个主要障碍。如今，pem - el需要稀有的铱和铂基催化剂。事实上，技术经济分析表明，当大规模生产时，PEM-EL电池组是电解槽中最昂贵的组件，而阳极电极（铱催化剂和传输层）将占电池组成本的大部分。因此，催化剂组成的多样化（即摆脱纯铱催化剂）代表了一个巨大的机会，可以使使用pem - el的绿色制氢实现显着增长。这一建议提供了一种新的和统一的策略来开发合成方法，并利用先进的材料特性来前馈到还原铱含量催化剂的设计中。我们将通过一种转化的方法来探索我们的电催化剂，从“模型系统”薄膜，到纳米粉末研究和商业相关测试，提供洞察哪些特性（电导率，固有活性，耐久性）决定和控制催化剂在这些不同的测试平台上的性能。此外，我们的合成方法，包括多磁控管系统的共溅射，将使催化剂组成的精度和灵活性大大提高。与我们的工业合作伙伴庄信万丰合作，最活跃的纳米粉末催化剂将使用工业测试协议对商业材料进行基准测试。在整个项目中，我们将利用一系列先进的材料表征技术，将结构和化学性质与催化剂性能联系起来，模拟电解槽工作中的操作条件。总之，本文提出的工作将实现纳米精度的催化剂，揭示设计策略并在操作条件下表征催化剂，从而加速可持续制氢的经济高效催化剂的开发。

Clean and sustainable hydrogen will have a major impact in the future of several sectors of our economy - from industrial processes (e.g. steel and concrete manufacturing), domestic and industrial heating, to the transportation sector (e.g. fuel cells and combustion engines), hydrogen offers many pathways to decarbonisation. This has been clearly articulated recently in the UK Government's Hydrogen Strategy. However, to enable hydrogen to fulfil its potential, it must be produced by renewable power, without carbon-emissions. Splitting water into hydrogen and oxygen with electricity (electrolysis) is one of the most promising technologies to meet this challenge. Indeed, commercialised electrolysers exist today that generate "green" hydrogen at industrially relevant scales. However, to date, 96% of hydrogen is produced from fossil fuel derived processes resulting in carbon-emissions. While a portfolio of electrolyser technologies will likely play important roles in the long term, proton exchange membrane electrolysers (PEM-ELs) are widely anticipated to provide the base capacity in the short and medium term. Despite this expectation, the high cost of green hydrogen from PEM-EL is a major barrier. PEM-ELs today require precious and scarce iridium and platinum-based catalysts. Indeed, technoeconomic analyses show that when manufactured at scale, the PEM-EL stack is the most expensive component of the electrolyser, and the anode electrodes (iridium catalyst and transport layers) will account for the majority of the stack cost. Diversification of catalyst composition (i.e. to move away from pure iridium catalysts) thus, represents a substantial opportunity that could enable significant growth in green hydrogen generation using PEM-Els. This proposal offers a novel and unified strategy to develop synthetic methods and utilise advanced materials characterisations to feed-forward into the design of reduced iridium-content catalysts. We will explore our electrocatalysts through a translational approach, from "model system" thin films, to nanopowdered studies and commercially relevant testing, providing insight into which properties (conductivity, intrinsic activity, durability) dictate and control catalyst performance across these different testing beds. Furthermore, our synthesis methods, including co-sputtering from multi-magnetron systems will enable precision and great flexibility in catalyst composition. Working with our industrial partner, Johnson Matthey, the most active nanopowder catalysts will be benchmarked against commercial materials using industrial testing protocols. Throughout the project, we will leverage an array of advanced materials characterisation techniques to correlate structural and chemical properties to the catalyst performance, mimicking the operating conditions within a working electrolyser. In summary, the proposed work herein will implement catalysts with nanometer precision, uncovering design strategies and characterising catalysts under operating conditions and therefore accelerating the development of cost-effective catalysts for sustainable hydrogen production.