Spectroscopy-driven design of an efficient photocatalyst for CO2 reduction (Ext.)

这是原奖学金“光谱学驱动的二氧化碳减排高效光催化剂设计”的延伸。在英国有足够的太阳能事件来提供我们所有的能源需求。然而，日晒水平在一天内和季节水平上变化很大。对于任何可行的能源技术来说，它的可靠性至关重要。克服供应间歇性问题的一个途径是利用太阳能驱动化学燃料的生产，这种燃料可以储存和运输，随时随地需要。可持续的碳基太阳能燃料和原料（如CH4、CH3OH、CO）可以通过光驱动水氧化与二氧化碳还原的耦合来生产。这是一个令人兴奋的前景，但要实现低碳强度燃料经济的目标，需要在燃料产生和利用系统方面取得突破。目前用于二氧化碳还原和水氧化的材料不能以可行的成本达到所需的效率和稳定性水平。同样，最有前途的清洁发电技术——碳燃料——燃料电池的效率也相对较低，而且不能容忍燃料原料中的杂质。最初的研究团队在研发新型低成本催化剂方面取得了巨大成功，这种催化剂既可以直接由阳光驱动（光催化剂），也可以间接使用电能（原则上可以来自光伏电池板），将二氧化碳转化为CO，这是一种重要的液体燃料前体。原始奖学金的一部分在英国开发了高灵敏度表面敏感光谱，IR-Vis和频率产生光谱的新能力。这个实验已被用于以令人难以置信的详细程度确定催化剂在表面的机制。这些，以及我们更广泛的光谱研究，对指导我们自己的催化剂设计方案至关重要。但对机械洞察的需求超出了我们自己的合成程序。对发生在电极和光电极表面的催化机制缺乏了解是整个领域的一个限制因素，阻碍了新材料的合理开发。因此，通过研究最先进的金属氧化物燃料电池，我们的光谱驱动计划将扩大到解决燃料生成的关键反应（水氧化和二氧化碳还原）以及燃料利用化学。该项目雄心勃勃，不仅旨在首次鉴定最常研究的光电极（赤铁矿）上水氧化过程中的所有关键中间体，而且还探索与水和电解质盐的二次相互作用如何控制活性。类似水平的机械细节也从领先的二氧化碳还原催化剂和燃料电池电极中寻求。我们旨在提供的这种机械细节水平可以改变我们自己，合作者和更广泛的社区材料开发计划。为太阳能燃料的生产和利用提供可扩展、高效的材料是一个具有挑战性的目标，但潜在的影响是巨大的。对现有材料表面机制的进一步了解将是实现这一目标的重要一步。

This is an extension of the original Fellowship "Spectroscopy-driven design of an efficient photocatalyst for CO2 reduction"There is sufficient solar energy incident on the UK to provide for all of our energy needs. However the insolation level varies hugely both within a day and on a seasonal level. For any energy technology to be viable it is essential that it is reliable. A route to overcoming the intermittency of supply issue is to use the solar energy to drive the production of a chemical fuel which can be stored and transported to be available when and where it is needed. Sustainable carbon-based solar fuels and feedstocks (e.g. CH4, CH3OH, CO) can be produced by the coupling of light driven water oxidation to the reduction of CO2. This is an exciting prospect but to realise the goal of low carbon-intensity fuel economy breakthroughs are required for both fuel generation and utilisation systems. Current materials for CO2 reduction and water oxidation do not achieve the required level of efficiency and stability at a viable cost. Similarly the most promising clean technologies for electricity generation on demand from carbon fuels, fuel cells, often suffer from relatively low efficiencies and intolerances to impurities in the fuel feed.The original fellowship has been highly successful in delivering new low-cost catalysts that can either be driven directly by sunlight (photocatalysts) or indirectly using electrical energy (which could in principle come from a PV panel) to reduce CO2 to CO, an important liquid fuel precursor. Part of the original fellowship developed new capabilities within the UK for a highly sensitive surface sensitive spectroscopy, IR-Vis Sum Frequency Generation Spectroscopy. This experiment has been used to identify with an incredible level of detail the mechanisms of catalysts at surfaces. These, and our wider spectroscopic studies, have been critical in guiding our own catalyst design programme. But the need for mechanistic insights extends beyond our own synthetic programme. A lack of understanding of the mechanisms of catalysis occurring on the surface of electrodes and photoelectrodes is a limiting factor for the entire field preventing the rational development of new materials. Therefore our spectroscopy driven programme will be expanded to address both the crucial reactions of fuel generation (water oxidation and CO2 reduction) as well as to fuel utilisation chemistry, through the study of state of the art metal-oxide fuel cells. The project is ambitious, aiming not just to provide the first identification of all key intermediates during water oxidation on the most commonly studied photoelectrode (hematite), but also to explore how secondary interactions with water and electrolyte salts control the activity. A similar level of mechanistic detail is also sought from leading CO2 reduction catalysts and fuel cell electrodes. This level of mechanistic detail that we aim to deliver could be transformative to our own, collaborators and the wider communities programmes of material development. The delivery of scalable, efficient materials for solar fuels production and utilisation is a challenging goal but the potential impact is enormous. An improved understanding of surface mechanisms on current materials would represent an important step towards this ambition.