Energy & Fuels, Vol.34, No.12, 16800-16809, 2020
Fe0.8Zn0.2 Nanoparticles Wrapped in Mesoporous Nitrogen-Doped Carbon Layers as Electrocatalysts for an Efficient Oxygen Reduction Reaction
An efficient oxygen reduction reaction (ORR) can be achieved by accelerating the movement of electrons, ions, reactants, and products. Here, we prepared core-shell nanohybrids with Fe0.8Zn0.2 nanoparticles wrapped in mesoporous nitrogen-doped carbon layers (Fe0.8Zn0.2@MNC). Due to partial volatilization, the sample has high porosity and conductivity, which provides fast-moving channels for electrons, ions, reactants, and products. The coupling effect of trace zinc and iron metal is beneficial to improve the catalyst activity. The results showed that the prepared Fe0.8Zn0.2@MNC catalyst has an advanced ORR activity through a four-electron transfer process in an alkaline medium. Moreover, the onset potential and the Tafel slope of Fe0.8Zn0.2@mNc can reach 0.965 V (vs reversible hydrogen electrode (RHE)) and 59.3 mV dec(-1), respectively, which are better than those for 20% Pt/C (0.943 V (vs RHE) and 75.1 mV dec(-1)). After durability tests, Fe0.8Zn0.2@MNC only shows a 3 mV negative shift of half-wave potential, which is much lower than 8 mV for 20% Pt/C.