Transition Metal Carbides for Electrochemical CO2 Reduction

用于电化学二氧化碳还原的过渡金属碳化物

• 批准号: 414298388
• 负责人: Professor Dr. Karsten Reuter
• 金额: --
• 依托单位: Institut für Physikalische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/414298388?language=en
• 关键词: Transition; Metal; Carbides; Electrochemical; CO2

Carbon dioxide (CO2) is the most notorious greenhouse gas that contributes to global warming. Converting produced CO2 into synthetic fuels represents thus a much sought route to reduce emissions and achieve a sustainable energy economy. Electrochemical CO2 conversion appears particularly advantageous, as it would draw the energy required to reduce the molecule directly from renewable electricity from wind, solar, or hydro power plants. It may furthermore be operated at ambient conditions and is therefore prone to small-scale decentralized utilization. Unfortunately, metal electrodes that are traditionally employed in electrochemistry show only an insufficient performance. The reaction runs too slow and too much energy is needed.These limitations are ascribed to a fundamental relation in the strength with which certain intermediate molecules that are formed in the course of the chemical reaction are bound to the metal electrodes. Modifying the metal electrode to optimize the binding of one such intermediate for the reaction automatically worsens the binding of another intermediate. There are first indications that this dilemma is broken when instead employing more complex electrode materials. Of interest are thereby either compound materials which mix metals with other elements or composite systems that comprise both a metal and another material. The objective of the present project is to assess the suitability of metal carbides in this respect, i.e. compounds formed of metals and the abundant element carbon. Specifically studied are molybdenum carbide and composite systems formed of molybdenum carbide and Au or Cu. Combining both experimental and computational approaches the ambitious goal is to analyze the electrochemical CO2 reduction at the atomic scale. Corresponding detailed insight is believed to provide a general understanding of how much and if so why the fundamental relation in the binding strength of the intermediate molecules is broken at these carbide based materials. This in turn will provide ideas of how to optimize carbides themselves for use as energy efficient electrodes in the electrochemical reduction of CO2, or design alternative materials for this purpose.

二氧化碳（CO2）是有助于全球变暖的最臭名昭著的温室气体。因此，将生产的二氧化碳转换为合成燃料代表了一条备受瞩目的途径，以减少排放并实现可持续的能源经济。电化学二氧化碳转化率似乎特别有利，因为它将从风，太阳能或水力发电厂从可再生电力中直接减少分子所需的能量。此外，它可能在环境条件下运行，因此容易出现小规模的分散利用。不幸的是，传统上在电化学中使用的金属电极仅表现出不足的性能。反应的运行太慢，需要太多的能量。这些局限性归因于某些在化学反应过程中形成的中间分子与金属电极结合的强度的基本关系。修改金属电极以优化一个这样的中间体对反应的结合会自动恶化另一个中间体的结合。有第一个迹象表明，当使用更复杂的电极材料时，这种困境会破裂。因此，有趣的要么是将金属与其他元素混合的复合材料，要么是构成金属和另一种材料的复合系统。本项目的目的是评估金属碳化物在这方面的适用性，即金属形成的化合物和丰富的元素碳。专门研究的是碳化物和复合系统由碳化物和铜或Cu形成的复合系统。结合实验方法和计算方法，雄心勃勃的目标是分析原子量表的电化学二氧化碳的减少。人们认为相应的详细见解提供了对中间分子结合强度的基本关系的一般性理解，为什么在这些基于碳化物的材料上破坏了中间分子的结合强度。反过来，这将提供有关如何优化碳化物自身作为在电化学减少二氧化碳或为此目的设计替代材料中的节能电极的想法。