Active sites and factors influencing them for efficient oxygen reduction reaction in metal-N coordinated pyrolyzed and non-pyrolyzed catalysts: a review
- 8 September 2017
- journal article
- review article
- Published by Royal Society of Chemistry (RSC) in Journal of Materials Chemistry A
- Vol. 5 (38), 20095-20119
- https://doi.org/10.1039/c7ta05222g
Abstract
With increasing demand for clean energy and approaching commercialization of polymer electrolyte membrane fuel cells (PEMFCs), replacing expensive Pt-based cathode catalysts with much cheaper non-precious metal (NPM) catalysts has become absolutely essential. This review highlights the parameters that have been considered vital to improving the overall performance of the NPM-based catalysts for oxygen reduction reaction (ORR). In the present review, we focus on well-known catalytic systems in three categories of NPM catalysts, i.e. biomimetic heme–copper oxidase enzymes, non-pyrolyzed/polymeric systems, and pyrolyzed NPM–nitrogen-doped carbon (M–N/C) (M = Fe, Ni, Co, etc.) catalysts. The ORR mechanism on the reported active sites and the effect of varying their local environments are considered and discussed in detail. Among all the catalysts, only pyrolyzed M–N/C catalysts have shown activity and stability much closer to that of the state-of-the-art commercial carbon-supported platinum (Pt/C) catalyst. Although great heights have been climbed in pyrolyzed M–N/C-based catalysts, still general consensuses need to be established regarding the active sites in the NMP-based M–N/C catalysts to help enhance the activity and stability of the catalytic system. By comparing the ORR mechanisms of the three studied systems, various similarities between the active sites are identified and reported comprehensively. On the basis of the information amassed, some future directions for improving the activity, selectivity, and durability of the NPM-based catalysts are also discussed.Keywords
Funding Information
- National Research Foundation of Korea (NRF-2011-0031571, NRF-2016M1A2A2937137)
This publication has 101 references indexed in Scilit:
- Nitrogen‐Enriched Core‐Shell Structured Fe/Fe3C‐C Nanorods as Advanced Electrocatalysts for Oxygen Reduction ReactionAdvanced Materials, 2012
- Iron porphyrin-based cathode catalysts for polymer electrolyte membrane fuel cells: Effect of NH3 and Ar mixtures as pyrolysis gases on catalytic activity and stabilityElectrochimica Acta, 2010
- Electrocatalytic activity and stability of substituted iron phthalocyanines towards oxygen reduction evaluated at different temperaturesElectrochimica Acta, 2008
- Fe/N/C non-precious catalysts for PEM fuel cells: Influence of the structural parameters of pristine commercial carbon blacks on their activity for oxygen reductionElectrochimica Acta, 2008
- Oxygen reduction by Fe-based catalysts in PEM fuel cell conditions: Activity and selectivity of the catalysts obtained with two Fe precursors and various carbon supportsElectrochimica Acta, 2006
- Activation and characterization of Fe-based catalysts for the reduction of oxygen in polymer electrolyte fuel cellsElectrochimica Acta, 1998
- Physical, chemical and electrochemical characterization of heat-treated tetracarboxylic cobalt phthalocyanine adsorbed on carbon black as electrocatalyst for oxygen reduction in polymer electrolyte fuel cellsElectrochimica Acta, 1995
- The removal of the type-2 copper from Rhus vernicifera laccaseBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1992
- On the effect of a heat treatment on the structure of carbon-supported metalloporphyrins and phthalocyaninesElectrochimica Acta, 1988
- Interpretation of the relative electrochemical activity of various metal phthalocyanines for the oxygen reduction reactionElectrochimica Acta, 1974