The carbon dots anchored Ag and Pd bimetallic as highly active and stable catalysts toward oxygen reduction reaction

Abstract

Although carbon-based catalysts show great potential in oxygen reduction reaction (ORR), it is still a challenge to increase their catalytic efficacy while reducing the amount of precious metals such as platinum and palladium. In this research, a palladium–silver bimetallic catalyst (Pd–Ag/CD) was flexibly synthesized through the in-situ self-reduction of palladium chloride and silver nitrate by carbon dots (CD). This novel catalyst displayed remarkable activity for the ORR, with peak potential, onset potential, and half-wave potential recorded at 0.89 V, 1.004 V, and 0.88 V, respectively. The exceptional performance of Pd–Ag/CD is attributed to the synergistic adjustment of the d-band by the palladium and silver metals, which optimizes the adsorption of oxygen and boosts the reaction's overall activity. Additionally, the slight negative shift of 12 mV in the half-wave potential after 5000 cycles indicates the catalyst's excellent durability. The findings of this study offer valuable theoretical insights for the development of carbon nanomaterial-based catalytic systems.