原子尺度上构筑超薄金属氧化物包碳纳米管载Pt催化剂及其稳定性研究

Proton exchange membrane fuel cells (PEMFCs) are a promising solution for clean energy technology because they offers high energy conversion efficiency, low emission of pollutants and environmentally friendly. However, the instability of carbon supported platinum (Pt) catalysts is a considerable challenge for widespread adoption of proton exchange membrane fuel cells in practical applications. The corrosion of carbon support and the weak interaction between Pt and support in the catalysts is one of the major factors affecting their stability. Herein, in this work, the advanced atomic layer deposition (ALD) technique is used to improve Pt stability by designing high stable support and increase the Pt-support interactions at atomic level. We first use ALD to prepare high stable ultrathin metal oxide (< 3nm) coated CNT composite support at the atomic level. Then the ALD is used to deposit Pt catalyst on ultrathin metal oxide coated CNT composite support and increase the Pt support interactions through precisely controlling the metal-support interface at the atomic level. Furthermore, we will study the stabilization mechanism for Pt supported on ultrathin metal oxide coated CNT composite support by combining morphology characterization, X-ray absorption spectroscopy, and density functional theory (DFT) calculations. This work will provide insights into the design of advanced catalyst support and improving the electro-catalyst stability.

质子交换膜燃料电池（PEMFC）作为一种理想的清洁能源，具有比功率高和环境友好等优点。然而，其商业碳载Pt基催化剂的低稳定性严重阻碍了PEMFC产业化发展进程。碳载体的电氧化和Pt-碳载体间弱的相互作用是导致Pt基催化剂稳定性差的主要因素。为此，申请人拟采用先进的原子层沉积（ALD）技术从原子尺度上设计高稳定的催化剂载体，并增强Pt-载体间的相互作用来制备高稳定Pt催化剂：首先从原子尺度上精确控制金属氧化物质量和厚度制备超薄金属氧化物（<3 nm）包碳纳米管复合载体，并从原子尺度上调控催化剂-复合载体间的界面，进一步增强Pt-金属氧化物间的相互作用，从而提高复合载体担载的Pt催化剂的稳定性；同时，通过形貌表征、同步辐射X-射线吸收光谱和密度泛函理论计算等来揭示复合载体的催化剂稳定机理。本项目研究成果对优化先进载体催化剂设计和提高其电化学稳定性具有重要的科学指导意义。

质子交换膜燃料电池（PEMFC）和可充电的锌空电池具有高能量密度、成本低、安全性、绿色环保等优点，被视为下一代可持续能源转换技术。然而，空气阴极在放电时所发生的氧还原反应（ORR）和充电时所发生的氧析出反（OER）应动力学缓慢、稳定性差，严重阻碍了质子交换膜燃料电池（PEMFC）和可充电的锌空电池产业化发展进程。为此，申请人从原子尺度上精确控制金属颗粒粒径及与载体间的相互作用，从而调控催化剂颗粒电子结构设计出高活性、高稳定的ORR/OER双功能催化剂，增强质子交换膜燃料电池（锌空电池性能。同时借助先进的测试技术和密度泛函理论计算探究过渡金属颗粒粒径、电子结构和催化活性之间的关系，揭示催化剂ORR/OER双功能催化反应机理。本项目将为原子尺度上设计先进催化剂发挥重要的作用.