Mechanistic aspects of electrocatalysis using metal oxide and sulphide electrode materials

使用金属氧化物和硫化物电极材料的电催化的机理

• 批准号: 2088628
• 金额: --
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2088628
• 关键词: Mechanistic; aspects; electrocatalysis; using; metal

Electrochemistry is now widely used to activate catalysts to perform a range of catalytic reactions, such as CO2 reduction. The two systems of interest in this project are copper and iron based oxide or sulphide catalysts. It has been shown that CO2, (although benign, but has significant effect on the climate change), can be activated to a more reactive state under electrochemical conditions using these catalysts. Whilst catalytic studies and many ex situ characterization methods have been employed to understand the nature of the catalyst, very little has been done to develop in situ methods to determine the nature of the catalyst under operating conditions, which is essential to determine the role of transient and steady state species responsible for catalytic reaction. This project will focus on developing in situ spectroscopic methods, in particular X-ray absorption spectroscopy (as it is element specific and does not require long-range order for structural study) and complementary infrared spectroscopy (which focuses on the vibrational modes of the reactants) to determine precisely the electronic and geometric state of the catalysts and reactants during reaction. The two systems we will use as exemplar for the study will be copper oxides and iron sulphides. Whilst there are research papers in this area, to our knowledge very little is known about the nature of metal centre (oxidation state, coordination) under reaction conditions. For example, both copper metal particles along with their oxides and Cu2O are the active phases present in the catalyst. Similarly, disordered (amorphous) FeS is proposed as active phase, but very little structural evidence is available in the literature.Therefore, the aim of this project is to develop in situ methods to understand the reacting and reactive state of copper and iron during electrochemical CO2 reduction, using X-ray absorption spectroscopy. Along with this in situ infra-red techniques will be used to monitor adsorbed reactants, intermediate and products at the electrode. The outcome will be a thorough understanding of the mechanism of catalysis of this important reaction.

电化学现在被广泛用于激活催化剂以执行一系列催化反应，如二氧化碳还原。这个项目中感兴趣的两个系统是铜和铁基氧化物或硫化物催化剂。研究表明，在电化学条件下，使用这些催化剂可以将二氧化碳(虽然无害，但对气候变化有重大影响)活化到更活跃的状态。虽然催化研究和许多非原位表征方法已被用于了解催化剂的性质，但很少有人开发原位方法来确定操作条件下催化剂的性质，这对于确定瞬时和稳态物种在催化反应中的作用至关重要。该项目将专注于开发原位光谱方法，特别是X射线吸收光谱(因为它是元素特有的，不需要进行结构研究的长程顺序)和互补红外光谱(侧重于反应物的振动模式)，以精确确定反应过程中催化剂和反应物的电子和几何状态。我们将使用的两个系统作为研究的样本将是铜氧化物和铁硫化物。虽然在这一领域有研究论文，但据我们所知，对反应条件下金属中心的性质(氧化态、配位)知之甚少。例如，铜金属颗粒及其氧化物和Cu2O都是催化剂中存在的活性相。类似地，无序(非晶态)FeS被认为是活性相，但文献中几乎没有结构证据。因此，本项目的目的是建立原位方法，利用X射线吸收光谱来了解铜和铁在二氧化碳电化学还原过程中的反应和反应状态。此外，现场红外线技术将用于监测电极上吸附的反应物、中间体和产物。其结果将是对这一重要反应的催化机理有一个彻底的了解。