Enhancing the oxygen reduction electrocatalytic activity of Pd/Carbon dots via Pd content tailoring

Abstract

In order to promote the application of carbon dots as carriers in oxygen reduction reaction, CD with uniform size distribution was prepared by microwave heating using citric acid and urea as raw materials through a bottom-up synthesis method. Due to the presence of a large number of hydroxyl groups on the surface of CD. We found that the prepared CD can be used as a reducing agent and stabilizer to directly reduce PdCl₂ to obtain Pd nanoparticles under oil bath conditions. The obtained Pd/CD system has excellent catalytic effect on the electrocatalytic oxygen reduction. The results show that the half-wave potential of Pd/CD-0.1 catalyst reaches 0.83 V, which is comparable to that of commercial Pd/C, and the corresponding limiting diffusion current density is even larger than that of commercial Pd/C catalyst. After a 5000 cycles stability test, the LSV exhibits a left shift of only 19 mV.