超薄多金属纳米晶组分异质性的精确调控及其电催化性能研究

Rationally designed synthesis of novel electrocatalysts with high activity, high selectivity and high stability is currently the key issue in the field of electrocatalytic energy conversion and storage. Noble metal nanocrystals exhibit outstanding and even irreplaceable performances for many electrocatalytic reactions. The electrocatalytic performance of noble metal nanocrystals depends on their electronic and surface structures that are highly affected by the compositions and elementary distributions. This project intends to start from the controlled synthesis of bimetal or multi-metal nanomaterials with ultrathin structures and then the precise regulation of the metal atom distributions to obtain compositional-heterogeneity-controlled multi-metal ultrathin nanocatalysts. With the structural advantages of ultrathin structures, such as large specific surface area and uniform coordinated surface atoms, we could compare the electrocatalytic properties of several typical ultrathin multi-metal products with different compositional heterogeneities. Combined with theoretical study, the structure-activity relationship between the compositional heterogeneity and the electrocatalytic performance would be established, and the mechanism for electrocatalytic enhancement of multi-metal nanocatalysts with specific compositional heterogeneity would be systematically expounded. Through the research, we prospect to establish some new methods for the synthesis of multi-metal nanocrystals with ultrathin structures and controlled composition heterogeneity, and illuminate the compositional heterogeneity effects in the electrocatalytic process to provide new ideas for the future design of efficient noble metal electrocatalysts.

设计合成高活性、高选择性和高稳定性的新型电催化剂是目前电催化能源转化和存储领域的核心课题。贵金属纳米晶在许多电催化反应中体现出不可被替代的优异性能。其电催化性能与晶体的电子结构和表面结构密切相关；而这两者很大程度上取决于组成和元素分布。本项目拟从具备超薄结构的二元或多元金属纳米材料的合成控制出发，在原子水平上精确调控特定超薄结构中的金属元素分布，得到组分异质性可控的超薄多金属纳米结构。借助超薄结构超大比表面积以及表面原子均一配位等结构优势，对几种形貌、组成相同但金属原子空间分布不同的超薄多元金属纳米晶进行电催化性能比较。结合理论研究，明确其组分异质性与电催化性能的构效关系，系统阐述特定组分异质结构对其电催化活性的增强机理。通过上述的探索，我们希望建立一些控制合成超薄多金属纳米晶体并调控其组分异质性的新方法，阐明电催化过程中的组分异质效应，为今后设计高性能贵金属纳米电催化剂提供新思路。

设计合成高效、稳定的新型电催化剂是能源转化与存储领域的核心课题之一。本项目以超薄/超细多元金属纳米材料为研究对象，针对其组分异质性的精确调控和电催化性能开展了系列研究，取得的主要研究成果如下：（1）发展了一种具有原子级分散氧化物-金属界面的二维反相纳米催化剂（RuOx-on-Pd）的构筑策略，实现高性能的Pd基氧还原电催化；（2）构筑了富含边缘催化活性位点的三元PdPtCu超薄纳米结构，实现20倍商业化Pt/C的乙醇电氧化性能；（3）基于Rh表面掺杂实现四元Pt基合金超细纳米线的结构强化和酸性条件下优异的甲醇电氧化性能；（4）基于表面Pt壳层原子逐层沉积技术，制备富含晶界缺陷的Rh@PtnL核壳超细纳米线，实现优异的乙醇电氧化性能；（5）发展了一锅液相分步还原法，一步合成具有超薄Pt3Ni{111}壳层的Pd@Pt3Ni核壳结构纳米枝，实现了显著增强的乙醇电氧化性能。我们进一步将上述主要策略拓展到其他研究体系，取得了一系列成果。通过项目实施，在包括Angew. Chem. Int. Ed., Nano Lett., Adv. Funct. Mater., Nano Energy等国内外知名学术期刊上共计发表了SCI收录论文13篇，其中SCI收录JCR 1区研究论文9篇，影响因子10以上研究论文7篇；申请了国家发明专利7项，已获授权2项。