Self-Templating Synthesis of N/P/Fe Co-Doped 3D Porous Carbon for Oxygen Reduction Reaction Electrocatalysts in Alkaline Media

Abstract

The development of low-cost, highly active, and stable oxygen reduction reaction (ORR) catalysts is of great importance for practical applications in numerous energy conversion devices. Herein, iron/nitrogen/phosphorus co-doped carbon electrocatalysts (NPFe-C) with multistage porous structure were synthesized by the self-template method using melamine, phytic acid and ferric trichloride as precursors. In an alkaline system, the ORR half-wave potential is 0.867 V (vs. RHE), comparable to that of platinum-based catalysts. It is noteworthy that NPFe-C performs better than the commercial Pt/C catalyst in terms of power density and specific capacity. Its unique structure and the feature of heteroatom doping endow the catalyst with higher mass transfer ability and abundant available active sites, and the improved performance can be attributed to the following aspects: (1) Fe-, N-, and P triple doping created abundant active sites, contributing to the higher intrinsic activity of catalysts. (2) Phytic acid was crosslinked with melamine to form hydrogel, and its carbonized products have high specific surface area, which is beneficial for a large number of active sites to be exposed at the reaction interface. (3) The porous three-dimensional carbon network facilitates the transfer of reactants/intermediates/products and electric charge. Therefore, Fe/N/P Co-doped 3D porous carbon materials prepared by a facile and scalable pyrolysis route exhibit potential in the field of energy conversion/storage.

Carbon-Based Electrocatalyst Design with Phytic Acid—A Versatile Biomass-Derived Modifier of Functional Materials

“… Electrocatalyst Precursors Doped Atoms (wt%) Surface Area (m 2 g −1 ) Porous Structure Ref. Template-Free Synthesis NPCNS_700T Phytic acid, chitosan N: 6.40 P: 5.80 - - [ 54 ] N,P-HLC Phytic acid, melamine, glucose N: 4.92 P: 0.55 422 - [ 65 ] FeP@SA-Fe/HC Phytic acid, melamine, iron nitrate, 2-aminoterephthalic acid N: 3.17 P: 4.55 Fe: 0.45 111 Average pore size: 3.87 nm [ 66 ] NPFe-C Phytic acid, melamine, iron(III) chloride hexahydrate N: 3.12 P: 3.51 Fe: 0.81 775 Micropore distribution: 0.90 nm Mesopore distribution: 2–35 nm [ 67 ] NP+NG/PG Phytic acid, 2,6-diaminopyridine, 5-aminouracil N: 4.52 P: 0.67 1114 Micropore distribution: 1–2 nm Mesopore distribution: 2–10 nm …”

Editorial for the Special Issue: “Advanced Nanomaterials for Electrochemical Energy Conversion and Storage”

“…Carbon-based doped nanomaterials are some of most widely studied catalysts. Rong et al [ 5 ] developed a self-template-assisted pyrolysis route to prepare a three-dimensional nanoporous carbon structure co-doped with N/P/Fe. The synthesis process is simple, avoiding the extra process of template removal, and the distribution and content of N/P/Fe can be well controlled.…”