Electrocatalytic, Kinetic, and Mechanism Insights into the Oxygen-Reduction Catalyzed Based on the Biomass-Derived FeOx@N-Doped Porous Carbon Composites

作者：Lu, Zhiwei^*; Chen, Jinpeng; Wang, WenLi; Li, Wenjin; Sun, Mengmeng; Wang, Yanying; Wang, Xianxiang; Ye, Jianshan^*; Rao, Hanbing^*

来源：Small, 2021, 17(19): 2007326.

DOI：10.1002/smll.202007326

• biomass derivative
• density function theory
• electrocatalysts
• Fe
• &#63743
• N co&#8208
• doped
• oxygen reduction reaction

A valid strategy for amplifying the oxygen reduction reaction (ORR) efficiency of non-noble electrocatalyst in both alkaline and acid electrolytes by decorated with a layer of biomass derivative nitrogen-doped carbon (NPC) is proposed. Herein, a top-down strategy for the generally fabricating NPC matrix decorated with trace of metal oxides nanoparticles (FeOx NPs) by a dual-template assisted high-temperature pyrolysis process is reported. A high-activity FeOx/Fe-N-C (namely Hemin/NPC-900) ORR electrocatalyst is prepared via simply carbonizing the admixture of Mg-5(OH)(2)(CO3)(4) and NaCl as dual-templates, melamine and acorn shells as nitrogen and carbon source, hemin as a natural iron and nitrogen source, respectively. Owing to its unique 3D porous construction, large BET areas (819.1 m(2)center dot g(-1)), and evenly dispersed active sites (Fe-N-x, C-N, and Fe-O parts), the optimized Hemin/NPC-900 catalyst displays comparable ORR catalytic activities, remarkable survivability to methanol, and preferable long-term stability in both alkali and acid electrolyte compared with benchmark Pt/C. More importantly, density function theory computations certify that the interaction between Fe3O4 nanoparticles and arm-GN (graphitic N at armchair edge) active sites can effectually promote ORR electrocatalytic performance by a lower overpotential of 0.81 eV. Accordingly, the research provides some insight into design of low-cost non-precious metal ORR catalysts in theory and practice.