Stoichiometry, hierarchical arrangement and kinetics of electrode reactions at novel multi-components electrocatalytic materials

新型多组分电催化材料电极反应的化学计量、分级排列和动力学

• 批准号: RGPIN-2019-05975
• 负责人: Mohamedi, Mohamed
• 金额: $ 1.75万
• 依托单位: Institut national de la recherche scientifique
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738633
• 关键词: Stoichiometry; hierarchical; arrangement; kinetics; electrode

The depletion of fossil fuel reserves and serious environmental issues has created tremendous energy challenges. It is now undeniable that electrochemistry- the interchange of chemical and electrical energy- is about to play a major role in energy production. As a clean, sustainable energy technology, direct ethanol fuel cells (DEFCs) have emerged as highly promising low carbon power sources for vehicles and as alternatives to rechargeable batteries in portable electronic devices. Yet, the commercialization of DEFCs is hindered by their low anode catalyst activities and the production of partial oxidation byproducts. In addition, proton exchange membranes-DEFCs are considered too bulky and costly, and they can be damaged by high concentrations of ethanol, known as the ethanol crossover effect. Our long-term objective is to develop membraneless mixed-reactants DEFCs (novel technology) with efficiency higher than 60%. Over the next five years, the main objective of our work is to develop and gain insights in the synthesis-structure-catalytic activity relationships of novel nanostructured highly active and efficient multicomponent anode catalysts for the electrocatalytic oxidation of ethanol (Theme I). Efforts will be focused on the addition of co-catalysts to platinum. We will choose materials composed of abundant and inexpensive metal oxide materials combined with ultra-low amounts of platinum and rhodium. We expect to discover the optimal structural arrangements of the atoms of the three components in the surface and bulk of the final active catalyst to maximize activity and selectivity. We will also develop selective cathode catalyst that is electroactive towards oxygen reduction reaction while tolerant to high concentrations of ethanol (Theme II). Considering that the size of oxygen molecule is much smaller than that of ethanol, our idea is develop a superficial material layer through which oxygen molecules can easily diffuse and be reduced at the platinum beneath layer surface while ethanol molecules remain impeded at the surface of the superficial layer. Like this higher ethanol concentrations could be used and superior electrochemical performance would be achieved. The results of this proposal will address Canada's research priority in the development of advanced nanomaterials based electrochemical clean/green technologies to deal with increasingly critical energy and environmental challenges as well as climate change, while training highly qualified personnel to exploit these opportunities. As to the fundamental issues, these studies will assist in establishing firm correlations between interfacial structures, compositions, and understanding of mechanistic aspects of new classes of catalytic materials. In addition, this proposed research program will be important to commercial applications in Canada such as, consumers' portable electronics and transport, or to specific users for road safety fuel cell-based sensors for ethanol detection.

化石燃料储量和严重的环境问题的消耗造成了巨大的能源挑战。现在不可否认的是，化学和电能的互换即将在能源生产中发挥重要作用。作为一种干净，可持续的能源技术，直接乙醇燃料电池（DEFC）已成为高度有希望的车辆低碳电源，并且是便携式电子设备中可充电电池的替代品。然而，DEFC的商业化受到低阳极催化剂活性和部分氧化副产物的产生的阻碍。此外，质子交换膜 - 脱酸被认为太笨重和成本很高，并且可能会被高浓度的乙醇（称为乙醇交叉效应）损坏。我们的长期目标是开发效率高于60％的无膜混合反应剂DEFC（新技术）。在接下来的五年中，我们工作的主要目的是开发并获得对新型纳米结构的合成结构催化活性关系的见解。努力将集中在将共催化剂添加到白金上。我们将选择由丰富且廉价的金属氧化物材料以及超低量的铂和菱形组成的材料。期望发现表面和大部分活性催化剂的三个成分原子的最佳结构排列，以最大程度地提高活性和选择性。我们还将开发选择性阴极催化剂，该催化剂对减少氧气反应具有电活性，同时耐受高浓度的乙醇（主题II）。考虑到氧分子的尺寸比乙醇小得多，我们的想法正在开发一个浅表材料层，氧分子可以很容易地扩散并在铂表面的铂表面下降低，而乙醇分子仍然障碍在表面的表面上。像这种更高的乙醇浓度可以使用，并且可以实现出色的电化学性能。该提案的结果将解决加拿大基于先进的基于纳米材料的电化学清洁/绿色技术的研究重点，以应对日益关键的能源和环境挑战以及气候变化，同时培训高素质的人员来探索这些机会。至于基本问题，这些研究将有助于建立界面结构，组成和对新催化材料机械方面的理解之间的牢固相关性。此外，该拟议的研究计划对于加拿大的商业应用将很重要，例如消费者的便携式电子和运输，或者对基于道路安全燃料电池的特定用户进行乙醇检测。