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

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 17; no. 19
• Main Authors: Lu, Zhiwei, Chen, Jinpeng, Wang, WenLi, Li, Wenjin, Sun, Mengmeng, Wang, Yanying, Wang, Xianxiang, Ye, Jianshan, Rao, Hanbing
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.05.2021
• Subjects: Biomass; biomass derivative; Carbon; Catalysts; density function theory; Density functional theory; Electrocatalysts; Electrolytes; Fe N co‐doped; Iron oxides; Melamine; Metal oxides; Nanoparticles; Nanotechnology; Nitrogen; oxygen reduction reaction; Oxygen reduction reactions; Pyrolysis; Survivability
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202007326

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 Mg5(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 m2∙g−1), and evenly dispersed active sites (FeNx, 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. Newly designed iron‐nitrogen‐co‐doped porous carbon material decorated with FeOx nanoparticles derived from biomass, which have large specific surface area, high degree of graphitization, and abundant atomically dispersed Fe‐Nx active sites, enhanced mass transport and O2 diffusion. Superior oxygen reduction reaction performance in both acidic and alkaline solution based on experiment and density function theory calculation was obtained.