Metal-organic framework thin films for electrocatalysis: A combined ex situ and in situ investigation

地球上的现代生活是由持续的能源供应维持的，目前超过80%的能源是由化石燃料碳源（煤、石油和天然气）提供的。气候变化危机，加上北海燃料资源的减少和全球化石燃料市场的波动，意味着迫切需要确保可持续能源的来源。在这种背景下，电化学技术由于其在能量转换、存储和化学工业中的突出作用而变得越来越重要。随着可再生电力成为英国政府能源政策的关键战略组成部分，加上近年来可再生电力成本的降低，电化学技术将在实现脱碳方面发挥关键作用。与电池一样，电催化正在成为能源技术（例如，电解槽和燃料电池）以及燃料和化学制造领域的一个成熟方向。应用包括：(i)二氧化碳的电化学转化以生产燃料和化学品（例如甲酸，合成气，乙醇），促进碳捕获和利用途径（CCU）， （ii）氧化低价值废弃化学品（例如生物柴油工业的甘油或PET消化的乙二醇）以产生化学工业使用的高价值产品。这种电力驱动过程的主要好处是它们对减少二氧化碳排放和向可持续社会过渡的贡献。然而，使电催化技术在经济上可行的关键挑战之一是开发廉价的催化剂，可以在电极上有效地驱动化学反应。在这种情况下，使用多孔材料作为催化剂是有吸引力的，因为它们具有较大的表面积，具有明确的孔隙和通道，具有完整的催化位点。金属有机骨架（MOFs）是一类具有永久孔隙率的微孔材料，其结构设计具有特殊的控制程度。虽然这些晶体材料在气体吸附、催化、能量储存、光收集等方面具有巨大的应用潜力，但由于电导率低，它们在电化学系统中的应用仍然存在问题，因此，该领域仍有许多问题有待解决。在这个提议中，我们的目标是获得关于这些材料如何作为电催化剂运作的基本见解。总的想法是，从这个项目中吸取的经验教训将融入下一代材料的设计原则。由于mof结构的复杂性，在操作条件下“可视化”其结构需要广泛的技术工具，包括光谱学，x射线衍射和成像。为此，我们将与国际研究人员合作，揭示材料的结构方面如何影响催化活性，以及材料在催化过程中是否进行结构重构。

Modern life on the planet is sustained by constant supply of energy, over 80% of which is currently provided by fossil-fuel-based carbon sources (coal, oil and gas). Climate change crisis, combined with dwindling North Sea fuel resources and volatility in the global fossil-fuel market mean there is a pressing need for securement of sustainable energy sources. In this context, electrochemical technologies are becoming increasingly important due to their prominent role in energy conversion, storage, and chemical industries. With renewable electricity being a key strategic component of UK Government's energy policy, coupled with cost reductions of renewable electricity in recent years, electrochemical technologies will play a key role in enabling decarbonisation. Alongside batteries, electrocatalysis is becoming a well-established direction in the domain of energy technologies (e.g., electrolysers and fuel cells) as well as fuels and chemical manufacturing. The applications include: (i) electrochemical conversion of CO2 to produce fuels and chemicals (e.g., formic acid, syngas, ethanol), facilitating carbon capture and utilisation pathways (CCU), (ii) oxidation of low-value waste chemicals (e.g., glycerol from biodiesel industry or ethylene glycol from PET digestion) to generate high-value products used by chemical industries. The primary benefit of such electricity powered processes is their contribution towards reducing the CO2 emission and transitioning to a sustainable society. However, one of the key challenges in making electrocatalytic technologies economically viable is developing inexpensive catalysts that can be used at the electrodes to drive the chemical reactions efficiently. In this context, use of porous materials as a catalyst is appealing because they have large surface area with well-defined pores and channels with integrated catalytic sites. Metal-organic frameworks (MOFs) are such a class of microporous materials with permanent porosity, and their structure can be designed with exceptional degree of control. While these crystalline materials have enormous potential for applications in gas sorption, catalysis, energy storage, light harvesting etc., their use in electrochemical systems has remained problematic due to low conductivity, and thus, many questions remain open in the field.In this proposal, we aim to gain fundamental insight on how these materials operate as electrocatalysts. The overall idea is that the lessons learned from this project will feed into the design principle of next generation of materials. Due to the structural complexity of the MOFs, 'visualising' their structure under operating condition requires a wide range of technical tools including spectroscopy, X-ray diffraction and imaging. For this purpose, we will team up with international researchers to uncover how structural aspects of the materials contribute to the catalytic activity and whether the materials undergo structural reconstruction during catalysis.