Preparation of Ag0 Nanoparticles by EDM Method as Catalysts for Oxygen Reduction

At present, platinum-based catalysts are the best cathode catalysts, but due to their high prices, they are difficult to use widely. Under alkaline conditions, silver is a better low-cost substitute. Here, a physical preparation method-electrical discharge machining (EDM)-is used to prepare Ag-0 nanoparticles. The method is simple and has a high yield. The diameter of prepared nanoparticles is about 30 nm and the nanoparticle surface is rich in defects. These defects enhance the adsorption of O-2. In addition, defects can cause tensile strain on the silver catalyst, causing the d-band center of silver to move upward. The defects and the upward shift of the d-band center jointly improve the adsorption energy and catalytic performance of Ag-0. This work provides a new method for the engineering construction of surface defects and the preparation of metal catalysts.