The Research On The Formation Mechanism Of Layered Growth And Island Growth Mode Of Pd@Pt Nano Catalyst And Their Catalytic Performance For The Hydrogen Evolution Reaction

As a clean energy, fuel cell has the advantages of high utilization rate and cause no pollution. The development and application of the fuel cell will alleviate the energy crisis. Fuel cell catalyst plays a key role in improving the conversion efficiency of the fuel cell, and continuously improve the catalytic effect of the catalyst will play a positive role in promoting the development of fuel cell.This master thesis aims at researching the main catalyst for the hydrogen fuel cell involved in hydrogen production steps, we design and develop of a new synthetic strategies:island growth mode and layered growth mode of the core-shell structure of the Pd@Pt. The formation mechanism of island growth mode and the catalyst application in fuel cell are also investigated.Under normal circumstances, when the lattice mismatch between the two metal atoms is very small, the core-shell structure tend to form a uniform distribution and layered growth mode structure. But in this thesis, we developed a new method for the synthesis of Pd@Pt nanocrystal with heterogeneous core-shell structure by using the induction of Br’ions.This synthetic strategies can generate regular core-shell structure of Pd@L-Pt and heterogeneous core-shell structure of Pd@I-Pt by controlling the adjustment of new generation Pt atoms in the distribution of Pd nanocubes structure surface.At the same time, the catalytic activity of the two catalysts were compared. In the hydrogen evolution reaction, which is a key step of hydrogen production technology in hydrogen fuel cell. The layered growth mode of Pd@L-Pt nanocrystal showed a slightly lower catalytic properties than the traditional commercial Pt/C catalyst, The reason for this phenomenon is that the Pd@L-Pt structure decreased the active area of the Pt within the unit mass; but island growth mode of Pd@I-Pt nanocrystal with the same Pt load amount showed excellent catalytic performance compared with the traditional Pt/C catalysts and Pd@L-Pt nanocrystal. Therefore, it is of great practical significance to develop a new type of Pd@I-Pt nanocrystal for improving the energy efficiency of the hydrogen fuel cell.