Metal–Nitrogen Doping of Mesoporous Carbon/Graphene Nanosheets by Self‐Templating for Oxygen Reduction Electrocatalysts

Abstract

We demonstrate a general and efficient self-templating strategy towards transition metal-nitrogen containing mesoporous carbon/graphene nanosheets with a unique two-dimensional (2D) morphology and tunable mesoscale porosity. Owing to the well-defined 2D morphology, nanometer-scale thickness, high specific surface area, and the simultaneous doping of the metal-nitrogen compounds, the as-prepared catalysts exhibits excellent electrocatalytic activity and stability towards the oxygen reduction reaction (ORR) in both alkaline and acidic media. More importantly, such a self-templating approach towards two-dimensional porous carbon hybrids with diverse metal-nitrogen doping opens up new avenues to mesoporous heteroatom-doped carbon materials as electrochemical catalysts for oxygen reduction and hydrogen evolution, with promising applications in fuel cell and battery technologies.

A graphene-directed assembly route to hierarchically porous Co–Nx/C catalysts for high-performance oxygen reduction

“…The existence of CoO may be due to the oxidation of Co nanoparticles exposed on the surface of carbon particles. 25 The Co-N and Co-O species can enhance ORR catalytic activity in alkaline conditions, while Co-N sites play a key role in ORR performance in acidic conditions. CoO and part of Co nanoparticles accessible to acid can be removed.…”

“…5 However, they have some drawbacks such as high cost, limited resources, low CO and methanol tolerance and poor durability, which severely hinder the commercialization of these electrochemical devices. [19][20][21][22][23][24][25][26] A great deal of research has been conducted to synthesize hierarchically nanoporous M-N x /C (M = Fe, Co) materials with a macro/meso/microporous structure as ORR electrocatalysts. [6][7][8][9][10][11][12][13][14][15][16][17][18] Among them, carbon-supported M-N x has received considerable attention because of their potential as electrocatalysts with high catalytic activity and selectivity, and excellent durability.…”

Scalable and Cost‐Effective Synthesis of Highly Efficient Fe2N‐Based Oxygen Reduction Catalyst Derived from Seaweed Biomass

“…The alternatives of Pt should have a comparable catalytic activity, but can be produced massively (very easy to scale up) and cost‐effectively from earth abundant resources. Ternary Fe/N/C has been considered as one of the most promising candidates due to its high ORR performance resulted from the synergistic effect of N and Fe, and its abundance in earth crust . For instance, Yin et al synthesis a hybrid of iron nitride and N‐doped graphene, which shows high ORR performance but not quite stable, through two step hydrothermal way and using expensive Fe phthalocyanine .…”

Cobalt–Nitrogen Co‐doped Carbon Nanotube Cathode Catalyst for Alkaline Membrane Fuel Cells

“…The total nitrogen content in Co/N/MWCNT‐1 catalyst was 3.3 at %, from which the relative amount of pyridinic‐N constitutes 51 %, quaternary (graphitic) N 18 %, pyrrolic‐N 23 % and pyridine‐N‐oxide 8 %. Reportedly, the percentage of pyrrole‐like nitrogen in the M/N/C catalysts should be lower than that of just nitrogen‐doped catalysts . The decrease in the amount of pyrrolic‐N has also been noted in the case of the Co/N/MWCNT‐1 catalyst in comparison to the same nitrogen precursor doped N/MWCNT material .…”