直接二甲醚燃料电池用长效高活性石墨烯负载低铂/非铂催化剂的可控合成及性能调控

With the environmental pollution and energy shortage affecting social, political and environmental, the developing of direct dimethyl ether fuel cell has recently received intensive interest. However, to enable direct dimethyl ether fuel cell for practical applications, numerous scientific challenges are urgently need to be overcome, but on the top of the list is the inferior performance of anodic catalyst. Therefore, there is an urgent need to design and synthesize highly efficient, stable, and low-cost electrocatalyst to significantly improve the energy conversion efficiency and reliability of the direct dimethyl ether fuel cell. To this end, by thorough analysis of the structure, physical and chemical properties of the dimethyl ether molecule and in light of the preliminary mechanism of the electrooxidation of dimethyl ether, this project will aim at design and synthesis of a series of advanced electrocatalyst with high activity, stability, and CO tolerance, by fully exerting and utilizing the favorable properties of graphene, including high conductivity, large surface area, and, especially, its unique interaction with the supported metal nanoparticles, and finely tuning the microstructure parameters the supported metal nanoparticles, composition, structure, morphology, size, and/or crystallinity. Furthermore, the underlying electrooxidation mechanism of dimethyl ether and the structure-performance relationship will also be intensively investigated with the help of detailed electrochemical characterization and analysis of the products and intermediates. The success of this project will open a new avenue to design and construct highly efficient and highly stable dimethyl ether electrooxidation catalyst, which may provide a scientific basis for improving the performance of direct dimethyl ether fuel cell and promoting their research and development.

直接二甲醚燃料电池的研究和开发对解决能源短缺和环境污染问题具有重要的科学意义和实用价值，设计和制备高活性、抗CO毒化和耐久性好的二甲醚电氧化催化剂是进一步提高其能量转换效率和可靠性，突破其发展和应用瓶颈的关键和难点。本项目基于二甲醚分子的结构和性质及其初步的电氧化机理，充分借助和发挥石墨烯自身的优异特性及其与担载金属纳米粒子的相互作用，调控活性组分组成、大小、形状、暴露晶面等与催化性能密切相关的微结构参数，使催化剂的表面赋予最适宜的活性中心；通过改变石墨烯表面缺陷位、官能团、掺杂等对石墨烯电子结构和表面特性进行调控，提高活性组分的分散性和稳定性，实现对催化剂综合性能的优化；揭示二甲醚电氧化反应机理及电催化剂的微结构参数与催化性能的构效关系。本项目将力求探索出一条设计和构筑高性能低成本二甲醚电氧化催化剂的新途径，为提高直接二甲醚燃料电池的性能，促进其研究和开发提供科学依据。

直接二甲醚燃料电池的研究和开发对解决能源短缺和环境污染问题具有重要的科学意义和实用价值，设计和制备高活性、抗CO毒化和耐久性好的二甲醚电氧化催化剂是进一步提高其能量转换效率和可靠性，突破其发展和应用瓶颈的关键和难点。我们通过对电化学表面面积（ECSA），电氧化活性，抗CO毒化能力，二甲醚（DME）的吸附能力的考察，发现具有大量连续表面的Pt催化剂对二甲醚的电氧化有较高活性；尺寸可控的碳载Pt纳米粒子对二甲醚电氧化的研究结果表明，催化剂的活性表面积、活性和电子转移系均随着Pt粒子尺寸的增加而成抛物线趋势变化，存在一个最优Pt粒子尺寸。我们的研究结果初步揭示了二甲醚电氧化反应机理及电催化剂的微结构参数与催化性能的构效关系，为设计和构筑高性能低成本二甲醚电氧化催化剂提供了新途径，为提高直接二甲醚燃料电池的性能，促进其研究和开发提供科学依据。