Sustainable Hydrogen Production from Seawater Electrolysis

海水电解可持续制氢

• 批准号: EP/W03784X/1
• 负责人: Wen-Feng Lin
• 金额: $ 32.22万
• 依托单位: Loughborough University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW03784X%2F1
• 关键词: Sustainable; Hydrogen; Production; Seawater; Electrolysis

Electrochemistry enables direct conversion between electrical and chemical energy with high efficiency, and is a key to achieving net zero. An exciting electrochemical technology is the hydrogen-oxygen (H2-O2) fuel cell that produces electricity at high efficiency with only clean water as the byproduct. A green and sustainable route for H2 production to support this technology is water electrolysis using renewable or excess electricity; however, it is an energetically uphill process involving the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode. Whilst the 2-electron HER is relatively facile, the 4-electron OER is particularly sluggish and requires noble metals (Ir, Ru) as catalysts under acidic conditions. Nevertheless, recently significant progress has been made (including some adventurous work by the applicant and their collaborators) towards more efficient OER under alkaline conditions, where non-noble metal catalysts such as transition metal (Ni, Fe) layered double hydroxides (LDHs) were effectively used. Notably, for water electrolysis to be used to store (as H2) a substantial portion of the world's energy, water distribution issues will arise as vast amounts of purified water will be needed. On the other hand, seawater is the most abundant aqueous electrolyte feedstock on Earth, but its implementation in the water-splitting process presents many challenges, especially for the anodic reaction. The most serious challenges in seawater electrolysis are posed by the chloride anions (around 3% NaCl in seawater by weight). Under acidic conditions, the OER equilibrium potential (1.23 V) is only slightly (130 mV) lower than that (1.36 V) of the chlorine evolution reaction (ClER); and OER as a 4-electron reaction requires a high overpotential while ClER is a facile 2-electron reaction with a kinetic advantage, thus CIER can compete with OER. However, in alkaline conditions, the equilibrium potential of OER is significantly shifted lower, e.g., 0.40 V at pH=14; while that of ClER does not change so much (1.36 V) but now the hypochlorite (ClO-) formation from chloride oxidation reaction (ClOR) must be considered as the latter has a relatively lower equilibrium potential of 0.88 V at pH=14; clearly now there is a significant difference of 480 mV in potential domain for OER to work before ClOR occurs.Within the above context, this exciting project aims to draw together the nascent work on new catalysts (including surface structures and layers) for the OER anode and HER cathode, the anion exchange membrane, membrane-electrode-assembly and reactor system development, in order to determine the feasibility of formulating low-cost and high performance (active and durable) electrodes and membrane-electrode-assemblies (MEAs) for a cost-effective and scalable seawater electrolyser for sustainable hydrogen production with the maximum resource and energy efficiencies. The proposed work is highly ambitious and high risk, as seawater electrolysis is very attractive but extremely challenging, ranging from competitive chloride oxidation to corrosive environments, which require highly selective electrocatalysts together with good stability at material level, and well-engineered electrodes and interfaces to facilitate mass transport (gas bubble removal) to enable high current density to be sustained at reactor level. However, if this feasibility research is successful, it will be extremely rewarding as it opens a new paradigm for low cost, large scale, and truly sustainable green hydrogen production for delivering sustainable net zero for the UK and beyond.

电化学能够高效地实现电能和化学能之间的直接转换，是实现净零的关键。一种令人兴奋的电化学技术是氢-氧（H2-O2）燃料电池，它以高效率产生电力，副产品只有清洁的水。支持该技术的用于H2生产的绿色和可持续的途径是使用可再生或过量电力的水电解;然而，它是涉及阴极处的析氢反应（HER）和阳极处的析氧反应（OER）的能量上的上坡过程。虽然2-电子HER相对容易，但4-电子OER特别缓慢，并且在酸性条件下需要贵金属（Ir，Ru）作为催化剂。尽管如此，最近已经取得了显著的进展（包括申请人及其合作者的一些冒险工作），以在碱性条件下更有效地OER，其中有效地使用了非贵金属催化剂如过渡金属（Ni，Fe）层状双氢氧化物（LDH）。值得注意的是，对于用于存储（作为H2）世界能量的相当大一部分的水电解，由于将需要大量的净化水，因此将出现水分配问题。另一方面，海水是地球上最丰富的含水电解质原料，但其在水裂解过程中的实施提出了许多挑战，特别是对于阳极反应。海水电解中最严重的挑战是氯阴离子（海水中氯化钠重量约为3%）。在酸性条件下，OER的平衡电位（1.23 V）仅略低于ClER的平衡电位（1.36 V）（130 mV），OER为4电子反应，需要较高的过电位，而ClER为2电子反应，具有动力学优势，可与OER竞争。然而，在碱性条件下，OER的平衡电位显著降低，例如，0.40 pH=14时的V;而ClER变化不大（1.36 V），但现在必须考虑由氯化物氧化反应（ClOR）形成次氯酸盐（ClO-），因为后者在pH=14时具有相对较低的0.88 V的平衡电位;显然，在ClOR发生之前，OER工作的电位域中存在480 mV的显著差异。在上述上下文中，这个令人兴奋的项目旨在将新催化剂的初步工作汇集在一起，（包括表面结构和层），阴离子交换膜，膜电极组件和反应器系统的开发，以确定制定低成本和高性能的可行性（活性和耐用）电极和膜电极组件（MEA），用于具有成本效益和可扩展的海水电解槽，以最大的资源和能源效率实现可持续的氢气生产。所提出的工作是非常雄心勃勃和高风险的，因为海水电解非常有吸引力，但极具挑战性，从竞争性氯化物氧化到腐蚀性环境，这需要高度选择性的电催化剂以及材料水平的良好稳定性，以及精心设计的电极和界面，以促进质量传输（气泡去除），以使高电流密度能够在反应器水平维持。然而，如果这项可行性研究取得成功，它将是非常有益的，因为它为低成本，大规模和真正可持续的绿色氢气生产开辟了一个新的范例，为英国和其他地区提供可持续的净零。

项目成果

Fast ion-conductive electrolyte based on a doped LaAlO3 with an amorphous surface layer for low-temperature solid oxide fuel cells

• DOI: 10.1016/j.jpowsour.2023.232723
• 发表时间: 2023-03
• 期刊: Journal of Power Sources
• 影响因子: 9.2
• 作者: Dan Xu;A. Yan;Yang Yang-Yang;Shifeng Xu;Yongjun Zhou;Shuangjun Yang;Wen-Feng Lin

Conductive core/shell polymer nanofibres as anode materials for direct ethanol fuel cells

• DOI: 10.1016/j.asems.2023.100070
• 发表时间: 2023-07
• 期刊: Advanced Sensor and Energy Materials
• 作者: A. Symillidis;S. Georgiadou;Wen-Feng Lin

Layer-structured Li1-xNaxNi0.8Co0.15Al0.05O2-d oxide anode for enhancing ceria electrolyte based solid ceramic fuel cell operating at lower temperatures down to 370 °C

层状结构Li1-xNaxNi0.8Co0.15Al0.05O2-d氧化物阳极可增强二氧化铈电解质基固体陶瓷燃料电池在低至370°C的低温下运行

• DOI: 10.1016/j.apenergy.2023.120788
• 发表时间: 2023
• 期刊: Applied Energy
• 影响因子: 11.2
• 作者: Huang L

Insights into the Origin of High Activity of Ni5P4(0001) for Hydrogen Evolution Reaction.

深入了解 Ni5P4(0001) 析氢反应高活性的起源。

• DOI: 10.17863/cam.95316
• 发表时间: 2023
• 作者: Yang Y