Preparation method, structural feature and application of carrying type nanometer electrocatalyst

Abstract

The invention relates to a preparation method, a structural feature and an application of a carrying type nanometer electrocatalyst. The preparation method comprises the following steps of: dispersing carriers such as carbon black into a hydrophobic solvent containing a surfactant, wherein the carriers provide supporting functions for supporting active sites for nucleating and growing of nanometer particles and the surfactant provides a template function for controlling the growing of the nanometer particles, and adding water-soluble metal salt and a reducing agent into a mixture having double functions of supporting and a template in a microcosmic reaction environment, so as to obtain the carrying type nanometer electrocatalysts with different carrying capacities; and carrying out washing for a plurality of times under a low temperature (100 DEG C), and effectively removing the surfactant and other side products in products. According to the preparation method, the structural feature and the application of the carrying type nanometer electrocatalyst, the average grain diameter is less than 5nm, and the size distribution is less than 20%; the operation of the method is simple, the reaction is quick, the nanometer electrocatalyst featured with the small average grain diameter, the narrow size distribution and high metal carrying capacity (50 Wt%) can be prepared, and the amplifying and the synthesizing are easy; and the prepared carrying type nanometer electrocatalyst can be applied to proton exchange membrane fuel cells.

Description

Technical field [0001] The invention belongs to the field of proton exchange membrane fuel cell catalysts, and specifically relates to a preparation method, structural features and applications of a supported nano electrocatalyst. Background technique [0002] Proton exchange membrane fuel cell (PEMFC), as a clean power generation technology, can efficiently convert chemical energy into electrical energy. Because of its advantages such as low operating temperature, fast start-up, and high energy density, it has attracted wide attention. Electrocatalyst is one of the core materials of PEMFC, and the synthesis of electrocatalyst is a focus of PEMFC research field. In recent years, domestic and foreign research institutions have carried out corresponding research and development work. [0003] Zhang et al. prepared a Pt / multi-walled carbon nanotube electrocatalyst by immersion reduction method. Pt particles of 6.5-7.5 nm were uniformly distributed on the surface of the support, and ...

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Problems solved by technology

However, the reaction temperature of this method is high (190°C), and the reaction steps are cumbersome, and a variety of stabilizers are used in the synthesis process, which are difficult to remove (J.B.Wu, J.L.Zhang, Z.M.Peng, H.Yang., et al. al. J. Am. Chem. Soc. 2010, 132, 4984)

[0008] The reported synthesis methods have problems such as high reaction temperature, long reaction time, difficult control, difficult removal of stabilizers, and unsuitability for large-scale synthesis.

Especially in the synthesis of high-loaded electrocatalysts, the size of nanoparticles increases and the particle size distribution is wide, resulting in reduced activity of electrocatalysts and prone to Ostwald aging

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