基于PtAu双金属/石墨烯复合纳米材料的直接醇类燃料电池新型阳极催化剂设计和性能研究

Direct alcohol fuel cell (DAFC) has the advantages, such as high energy density, simple structure, easy storage of fuel, etc., which make it currently become the most potential electric supply. However, the main problems in its key component, anodic catalysts, such as low catalytic efficiency, weak resistant to CO poisoning and poor durability, restricted DAFC commercializing. Considering these problems and our previous results, this proposal was suggested to prepare graphene supported PtAu nanomaterials as new anodic catalyst under the guidance of the theoretical calculation, in which good nature of graphene as carriers and high performance of PtAu double metal materials toward alcohol oxidation would be combined. The effect of preparation conditions on the morphology and structure of PtAu nanocrystals would be investigated to fulfill controllable growth of nanocrystals on graphene. We would systematically evaluate electrocatalytic performance of the nanocomposites toward alcohol oxidation (Methanol and Ethanol). It would be mainly illustrated the inner structure-activity relationship between the morphology and surface structure of PtAu nanocrystals on graphene and its ability toward CO poisoning resistance and alcohol molecules catalytic oxidation. Through revealing the mechanism of graphene and Au on enhanced catalytic performance and the related electrocatalytic oxidation, we hope to develop stable, efficient and economic electrocatalyst for DAFC. The project can provide theoretical support and technical guidance for the commercialization of DAFC.

直接醇类燃料电池具有能量密度高、结构简单、燃料易储存等特点，使其成为现今最具潜力的动力电源。而其关键材料阳极催化剂催化活性低、抗CO中毒能力弱和较高的成本是制约醇类燃料电池商业化的关键问题。针对此问题并结合已有工作基础，本项目提出在理论计算的指导下，将石墨烯优良的载体性质与PtAu双金属纳米材料对于醇类小分子的高催化活性相结合，制备石墨烯载PtAu复合纳米材料新型阳极催化剂。研究制备条件对PtAu纳米晶的形貌和结构的影响，实现对石墨烯表面PtAu纳米晶可控生长；系统研究该复合材料对醇类小分子（甲醇和乙醇）的电催化性能，重点阐明石墨烯表面PtAu纳米晶形貌、表面结构与其对CO抗毒化和醇类小分子催化性能的内在构效关系，揭示石墨烯和金的催化增强机制以及相关电催化氧化反应机理，获得稳定、高效、经济的直接醇类燃料电池新型阳极催化剂。本项目将为直接醇类燃料电池的商业化应用提供理论支持和技术指导。

直接醇类燃料电池具有能量密度高、结构简单、燃料易储存等特点，使其成为现今最具潜力的动力电源。而其关键材料阳极催化剂催化活性低、抗CO中毒能力弱和较高的成本是制约醇类燃料电池商业化的关键问题。本项目在理论计算的指导下，将石墨烯优良的载体性质与PtAu 双金属纳米材料对于醇类小分子高催化活性相结合，制备石墨烯载PtAu复合纳米材料新型阳极催化剂。研究制备条件对PtAu纳米晶的形貌和结构的影响，实现对石墨烯表面PtAu纳米晶可控生长；系统研究该复合材料对醇类小分子（甲醇和乙醇）的电催化性能，重点阐明石墨烯表面PtAu纳米晶形貌、表面结构与其对CO抗毒化和醇类小分子催化性能的内在构效关系，揭示石墨烯和金的催化增强机制以及相关电催化氧化反应机理，获得稳定、高效、经济的直接醇类燃料电池新型阳极催化剂。 . 依靠理论计算和模拟，从热力学和动力学两方面考察石墨烯作为载体和Au的加入对于 Pt电子结构、CO 吸附、醇类分子吸附反应的影响，理论计算结果表明Pt的d带中心能级随着Au的引入，逐渐向费米能级移动，这证明了Au引入影响了复合材料整体的电子结构，不仅提升了电催化剂的催化活性，也有助于增强电催化剂对于CO的抗毒化性能；在理论计算指导下，采用电化学法和化学还原法，成功制备多种形貌和结构的石墨烯负载的PtAu复合纳米材料，实现了石墨烯表面PtAu纳米材料的可控生长；系统研究制备条件对石墨烯表面PtAu纳米晶物相的影响及其对甲醇催化性能的影响；采用XRD及XPS研究了石墨烯表面PtAu纳米晶结构和电子态的变化情况，探究石墨烯表面PtAu纳米晶合金对于甲醇催化增强机理。理论计算模拟和具体实验研究均指明具有合适成分（Pt：Au 为1:3）比例的PtAu双金属合金/石墨烯复合纳米材料展现了明显优于商业铂黑和单一金属/石墨烯材料的催化活性和对一氧化碳的抗毒化能力，该石墨烯复合材料在高性能的燃料电池阳极催化材料方面有较大的潜在应用价值。