3D Melamine Sponge-Derived Cobalt Nanoparticle-Embedded N-Doped Carbon Nanocages as Efficient Electrocatalysts for the Oxygen Reduction Reaction

Hua Zhang; Yao Zhou; Ji Chen; Ziqiu Wang; Zitao Ni; Qianwen Wei; Anran Chen; Meng Li; Tao Sun; Zhang Jin; Thomas Wågberg; Guangzhi Hu; Xifei Li

doi:10.1021/acsomega.1c01036

3D Melamine Sponge-Derived Cobalt Nanoparticle-Embedded N-Doped Carbon Nanocages as Efficient Electrocatalysts for the Oxygen Reduction Reaction

ACS Omega. 2021 Jul 27;6(31):20130-20138. doi: 10.1021/acsomega.1c01036. eCollection 2021 Aug 10.

Authors

Hua Zhang¹, Yao Zhou², Ji Chen¹, Ziqiu Wang³, Zitao Ni¹, Qianwen Wei¹, Anran Chen¹, Meng Li⁴, Tao Sun¹, Zhang Jin¹, Thomas Wågberg⁵, Guangzhi Hu^{1

4}, Xifei Li⁶

Affiliations

¹ School of Materials and Energy, Yunnan University, Kunming 650091, P. R. China.
² School of engineering, University of Edinburgh, Edinburgh EH9 3JW, England.
³ MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou 310027, P. R. China.
⁴ College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450000, P. R. China.
⁵ Department of Physics, Umeå University, SE-90187 Umeå, Sweden.
⁶ Xi'an Key Laboratory of New Energy Materials and Devices, Institute of Advanced Electrochemical Energy & School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, China.

Abstract

The large-scale and controllable synthesis of novel N-doped three-dimensional (3D) carbon nanocage-decorated carbon skeleton sponges (Co-NCMS) is introduced. These Co-NCMS were highly active and durable non-noble metal catalysts for the oxygen reduction reaction (ORR). This hybrid electrocatalyst showed high ORR activity with a diffusion-limiting current of 5.237 mA·cm^-2 in 0.1 M KOH solution through the highly efficient 4e^- pathway, which was superior to that of the Pt/C catalyst (4.99 mA·cm^-2), and the ORR Tafel slope is ca. 67.7 mV·dec^-1 at a high potential region, close to that of Pt/C. Furthermore, Co-NCMS exhibited good ORR activity in acidic media with an onset potential comparable to that of the Pt/C catalyst. Most importantly, the prepared catalyst showed much higher stability and better methanol tolerance in both alkaline and acidic solutions. The power density obtained in a proton exchange membrane fuel cell was as high as 0.37 W·cm^-2 at 0.19 V compared with 0.45 W·cm^-2 at 0.56 V for the Pt/C catalyst. In Co-NCMS, the N-doped carbon nanocages facilitated the diffusion of the reactant, maximizing the exposure of active sites on the surface and protecting the active metallic core from oxidation. This made Co-NCMS one of the best non-noble metal catalysts and potentially offers an alternative approach for the efficient utilization of active transition metals in electrocatalyst applications.