(544gf) Tuning Cobalt and Nitrogen Co-Doped Carbon Nano Composites for Efficient Oxygen Reduction Reaction

Liu, Y., Guangdong University of Technology
Liu, M., Peking University
Min, Y., Guangdong University of Technology
The electrocatalytic performance and cost of ORR catalysts is crucial to many renewable energy conversion and storage systems/devices. Recently, transition metal−nitrogen doping carbon catalysts (M-N-C) have attracted tremendous attention, which is effective to reduce costs and exhibit excellent catalytic activity, but is restricted large-scale commercial applications by complex preparation processing. Rational design of fabricating highly efficient M-N-C catalysts for ORR is of great importance. Here, a novel and facile strategy to prepared Co-N-C catalyst is developed. Nano carbon composites are used to associated transition metal cobalt salt and followed pyrolysis strategy at 700-900 °C under argon atmosphere. The composites play a multiple role simultaneously, including structural support, dispersing cobalt ions by coordinate bonds, providing carbon & nitrogen source and so on. Attributed to the conductive carbon frameworks and abundant catalytic sites, the Co-N-C catalyst exhibits excellent electrocatalytic performance. A high onset potential (0.96 V vs. reversible hydrogen potential, RHE) and half-wave potential (0.80 V vs. RHE) and a large diffusion-limited current density (4.65 mA cm−2) are achieved for ORR, comparable to or exceeding the commercial 20% Pt/C and reported M-N-C ORR electrocatalysts. This work provides a universal dispersion technology for Co-N-C catalyst that makes it a very promising candidate toward ORR.