担载型纳米金的制备参数优化及电催化性能探索

纳米尺度的金由于常表现出有趣的尺寸效应和物理化学特性而被大量应用于催化反应中，但是其在电催化反应中的应用却十分有限. 本文以水为溶剂、HAuCl₄为前驱体、十二烷基聚乙二醇醚（Brij 35）等为软模板剂、NaBH₄为还原剂、活性炭或石墨烯为载体，在温和反应条件下获得担载型金纳米电催化剂. 本文考察并优化了关键制备参数和样品纯化方法，最终确定NaBH₄的最佳浓度区间为5 ~ 10mmol•L^-1，Brij 35的最佳浓度约为1 mmol•L^-1，在3 ~ 16 ^oC下金纳米颗粒的尺寸容易控制，石墨烯和活性炭（EC600）是金纳米颗粒的良好载体. 在优化的反应条件下，金纳米颗粒的粒径可以被控制在1 ~ 4 nm. 热处理法可以有效去除表面活性剂，纯化后的担载型纳米金电催化剂在醇类小分子的氧化反应中表现出良好的性能.

Preparation Parameters Optimization and Electrocatalytic Properties of Supported Au Nanoparticles

Due to interesting size effect, physical and chemical properties, nano-scale gold materials have been commonly used to catalytic reactions. However, the application of gold nanomaterials in the field of electrocatalysis is limited. Herein, we report the synthesis of gold nanparticles supported on carbon through chemical reduction of HAuCl₄ by NaBH₄ under mild conditions in the presence of surfactants as soft templates, carbon black or graphene as a support. We investigated a series of key reaction parameters, including reagent concentration, temperature, the types of carbon supports and surfactants. With the optimum synthetic parameters, we successfully obtained supported 1 ~ 4 nm gold particles. In addition, we found that the heat treatment could effectively remove such a surfactant as Brij35. The purified electrocatalysts demonstrated electrocatalytic activities toward both oxygen reduction reaction and alcohol oxidation reaction.