EAGER: Identifying Active Sites in Electrocatalysis by Steady-State Isotope-Transient Technique

EAGER：通过稳态同位素瞬态技术识别电催化活性位点

• 批准号: 1835967
• 负责人: Adam Holewinski
• 金额: $ 10.49万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1835967&HistoricalAwards=false
• 关键词: EAGER; Identifying; Active; Sites; Electrocatalysis

The project will develop and apply new methods to understand molecular-level processes applicable to the design of catalysts for direct methanol fuel cells (DMFCs). Fuel cells utilizing liquid fuels pose benefits in energy density, safety, and ease of fuel transport and storage. DMFCs, in particular, are attractive because of ready availability of methanol, and the potential for producing methanol from renewable resources. However, the low energy conversion efficiency of current DMFC technology has curtailed widespread use. This work will provide detailed understanding of the catalytic reactions that occur in a DMFC, such that more efficient catalyst materials and structures may be proposed. The methods developed should advance direct methanol fuel cell technology along the path toward broader commercial application, thereby enabling cleaner and more efficient energy production.The project will enable a new method for operando counting of active catalytic sites via the first demonstration of liquid-phase electrochemical steady-state isotope-transient kinetic analysis (SSITKA). The method development will utilize - as a probe system - the electrochemical methanol oxidation reaction (MOR) over carbon-supported platinum (Pt) and platinum-ruthenium (PtRu). On these materials, the MOR involves several well-known intermediates, and it yields products that are amenable to characterization by both SSITKA and auxiliary techniques that can corroborate SSITKA data. Complementary analyses, including in-situ infrared spectroscopy and numerous X-ray and electron-based materials characterization techniques, will be used to inform a holistic examination of the reaction mechanism. New understanding will be generated along several lines of inquiry as captured in two themes. Theme I will focus on experimental kinetics, and will link SSITKA data - obtained across a range of experimental conditions, catalyst particle sizes, and catalyst compositions - to microkinetic models that relate current-voltage characteristics to possible elementary steps. Theme II will utilize a broad range of ex-situ and in-situ characterization methods to identify and control active sites as a function of catalyst composition and synthesis methods. Taken together, the two themes should generate unprecedented insight regarding the factors that control activity and selectivity of catalytic electrochemical methanol oxidation, while also providing a platform for development and refinement of the SSITKA technique. From a technological point of view, the fundamental understanding enabled by the SSITKA technique with respect to kinetics, detailed reaction mechanisms, and catalyst structure-function relationships will be translatable to a broad range of electrochemical reactions. In combination with other techniques, it will provide insight regarding active materials and surface structures that will guide the design of better-performing catalysts. The project will also support graduate and undergraduate education in the area of electrochemistry and renewable energy, as well as several educational and outreach activities already under development by the principal investigator.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目将开发并采用新方法来了解适用于直接甲醇燃料电池催化剂（DMFC）的分子级过程。 利用液体燃料的燃料电池在能量密度，安全性以及燃料传输和储存方面造成了良好的利益。 尤其是DMFC由于现成的甲醇供应以及从可再生资源产生甲醇的潜力而具有吸引力。 但是，当前DMFC技术的低能转化效率已限制了广泛使用。 这项工作将提供对DMFC中发生的催化反应的详细理解，从而可以提出更有效的催化剂材料和结构。开发的方法应沿着通往更广泛的商业应用的路径推进直接的甲醇燃料电池技术，从而实现清洁剂和更有效的能源生产。该项目将通过首次演示液相电化学稳态稳态同位素 - 转移性动力学分析（SSITKA（SSITKA），可以实现一种新的方法来进行操作的活性催化位点。 该方法的开发将在碳支持的铂（PT）和铂正森（PTRU）上使用 - 作为探针系统 - 电化学甲醇氧化反应（MOR）。 在这些材料上，MOR涉及几个众所周知的中间体，并产生可以通过SSITKA和辅助技术来证实可以证实SSITKA数据的产品。 互补分析，包括原位红外光谱以及许多X射线和电子基材料表征技术，将用于为反应机制进行整体检查。将在两个主题中捕获的几条询问中产生新的理解。主题I将重点放在实验动力学上，并将将SSITKA数据联系起来 - 在一系列实验条件，催化剂粒度和催化剂组合物中获得的SSITKA数据与将电流 - 电压特性与可能的基本步骤相关联的微动模型。主题II将利用广泛的前置和原位表征方法来识别和控制活性位点，这是催化剂组成和合成方法的函数。综上所述，两个主题应就控制催化电化学甲醇氧化的活性和选择性的因素产生前所未有的见解，同时还为SSITKA技术的开发和改进提供了平台。 从技术的角度来看，SSITKA技术对动力学，详细的反应机制和催化剂结构 - 连接关系的基本理解将被翻译成广泛的电化学反应。结合其他技术，它将提供有关活性材料和表面结构的见解，这些材料和表面结构将指导表现效果更好的催化剂的设计。该项目还将支持首席研究员已经开发的电化学和可再生能源领域的研究生和本科教育，以及几项已经开发的教育和外展活动。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响审查的评估来通过评估来支持的。