Microwave-assisted synthesis of carbon-supported Pt nanoparticles for their use as electrocatalysts in the oxygen reduction reaction and hydrogen evolution reaction

Pt nanoparticles were incorporated on carbon black (Vulcan XC-72R) and an activated carbon (F400) using a fast and efficient microwave method. For the preparation, a Pt solution was contacted with the corresponding carbon sample and heated up to 110°C in a microwave oven using an optimised heating rate. TEM images revealed that the carbon-supported Pt nanoparticles had a small average particle size and high dispersion. These Pt-based electrocatalysts showed both high electrocatalytic activity and selectivity towards the 4-electron pathway for the oxygen reduction reaction (ORR) in acid and alkaline media. In addition, they presented excellent stability and resistance to CO poisoning. Moreover, the as-prepared electrocatalysts exhibited outstanding electrocatalytic behaviour for the hydrogen evolution reaction (HER). It should be highlighted that, even though our Pt-based electrocatalysts have much lower loadings than that of the commercial Pt/C sample (used as reference), the electroactive surface areas of as-prepared electrocatalysts were higher compared to the reference electrocatalyst. Such small and well-dispersed Pt NPs with an enhanced electroactive surface area and strong interaction with the carbon support, led to an improvement of the current density normalised by Pt loading (A gPt−1). The authors would like to thank PID2019-105923RB-I00 and PID2021-123079OB-I00 projects project funded by MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe”, the Generalitat Valenciana (GRISOLIA/2020/114) and CONACYT project SEP-CB-2014-01-237118 and FORDECYT-2018-8-297525 for their financial support.