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）是导致全球变暖的最臭名昭著的温室气体。因此，将产生的二氧化碳转化为合成燃料是减少排放和实现可持续能源经济的一条广泛寻求的途径。电化学二氧化碳转化似乎特别有利，因为它可以直接从风能、太阳能或水力发电厂的可再生电力中获取减少分子所需的能量。此外，它可以在环境条件下操作，因此易于进行小规模分散利用。不幸的是，传统上用于电化学的金属电极仅表现出不足的性能。反应进行得太慢，需要太多的能量。这些限制归因于在化学反应过程中形成的某些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其中一种中间体的结合，从而自动恶化另一种中间体的结合。有初步迹象表明，当采用更复杂的电极材料时，这种困境就被打破了。因此，感兴趣的是将金属与其他元素混合的复合材料或既包括金属又包括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，即由金属和丰富的碳元素组成的化合物。具体研究了碳化钼和碳化钼与金或铜形成的复合体系。结合实验和计算方法，雄心勃勃的目标是在原子尺度上分析电化学二氧化碳还原。据信，相应的详细见解提供了对中间分子结合强度的基本关系在这些碳化物基材料中被破坏的程度和原因的一般理解。反过来，这将提供如何优化碳化物本身作为电化学减少二氧化碳的节能电极的想法，或为此目的设计替代材料。