Electrochemical properties of Metal Oxide Epitaxial Catalysts

氢气的生产是储存可持续能源的有前途的解决方案之一。氢气被认为是未来清洁能源的一种优良来源。其生产通过水分解（WS）使用可再生能源电力（太阳能，风能等）。是一种高效的无二氧化碳工艺。使用燃料电池将其转换回电力也是无二氧化碳的。WS包括阴极处的析氢反应（HER）和阳极处的析氧反应（OER）。WS电池领域的主要目标之一是降低驱动这两个反应所需的电势差，即，设计用于HER和OER的高效催化剂。因此，尽管大气中丰富的O2不是燃料电池技术中的限制性化合物，但其有效生产是以低电力成本将可持续能源转化为电力的直接手段。用于WS的有效催化剂通常基于Pt族金属，其不提供用于大规模H2生产的经济上可行的解决方案。最近的研究试图设计新的WS无Pt催化剂。他们中的一些人已经表明，铁族金属的氧化物是有效的OER催化剂的非常好的候选者，并且它们满足可持续WS技术的所有上述要求。这一有前途的研究领域仅限于其前提，对这些氧化物的催化反应机制知之甚少。我们相信，为了解开反应机理而合成模型催化剂的任何新策略都将是向前迈出的一步，以显著提高能量转化，并将产生巨大的经济影响。MEC目标是使用室温电化学合成具有限定结构性质的Fe族金属和合金氧化物层，并理解这些氧化物催化性质与它们的原子尺度结构之间的关系，以设计新的氧化物催化剂用于改善WS电池中的OER。本论文将利用最新技术研究氧化物催化剂在反应条件下的催化性能和结构。该项目是一个法德共同项目，合作伙伴EP（Ecole Polytechnique，帕莱索，法国）和合作伙伴IEAP（Institute of Experimental and Applied Physics，University of基尔，德国）将由EP实施。它还将受益于EP合作伙伴和Jeffrey格里利（美国普渡大学）团队之间的现有合作，该团队对电化学环境中的金属氧化物进行密度泛函理论计算。

The production of H2 is one of the promising solutions to store sustainable energy. H2 is considered as an excellent source of clean energy for the future. Its production through water splitting (WS) using renewable energy power (solar, wind etc.) is an efficient CO2-free process. Its conversion back to electrical power using fuel cells is also CO2-free. WS consists in the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode. One of the major goals in the field of WS cells is the decrease of the potential difference necessary to drive these two reactions, i.e., the design of efficient catalysts for HER and OER. Hence, even though O2 which is abundant in the atmosphere is not a limiting compound in fuel cell technology, its efficient production is a direct means to convert sustainable energy into electrical power at a low power cost. Efficient catalysts for WS are generally based on Pt-group metals which do not present an economically viable solution for large scale H2 production. Recent studies attempted at designing new WS Pt-free catalysts. Some of them have shown that oxides of the Fe-group metals are very good candidates for efficient OER catalysts and that they meet all above requirements for a sustainable WS technology. This promising field of research is only at its premises and not much is known about the catalytic reaction mechanisms of these oxides. We believe that any new strategy to synthesize model catalysts in order to unravel the reaction mechanisms will be a step forward to significantly improve energy conversion and will have a large economical impact.EC-MEC targets synthesizing Fe group metal and alloy oxides layers with defined structural properties using room temperature electrochemistry and understanding the relation between these oxides catalytic properties and their atomic scale structure to design new oxide catalysts for improved OER in WS cells. State of the art techniques will be utilized to investigate in-operando conditions the catalytic properties and structure of oxide catalysts in reaction conditions. The project is a French-German common project with Partner EP (Ecole Polytechnique, Palaiseau, France) and Partner IEAP (Institute of Experimental and Applied Physics, University of Kiel, Germany) which will be conducted by EP. It will also benefit from an already existing collaboration between EP partner and the group of Jeffrey Greeley (Purdue University, USA), which performs Density Functional Theory calculations on metal oxides in the electrochemical environment.