Novel cost‐effective fuel cells have become more attractive due to the demands for rare and expensive platinum‐group metal (PGM) catalysts for mitigating the sluggish kinetics of the oxygen reduction reaction (ORR). The high‐cost PGM catalyst in fuel cells can be replaced by Earth‐abundant transition‐metal‐based catalysts, that is, an Fe–N–C catalyst, which is considered one of the most promising alternatives. However, the performance of the Fe–N–C catalyst is hindered by the low catalytic activity and poor stability, which is caused by insufficient active sites and the lack of optimization of the triple‐phase interface for mass transportation. Herein, a novel Fe–N–C catalyst consisting of mono‐dispersed hierarchically mesoporous carbon sphere cores and single Fe atom‐dispersed functional shells are presented. The synergistic effect between highly dispersed Fe‐active sites and well‐organized porous structures yields the combination of high ORR activity and high mass transfer performance. The half‐wave potential of the catalyst in 0.1 M H2SO4 is 0.82 V versus reversible hydrogen electrode, and the peak power density is 812 mW·cm−2 in H2–O2 fuel cells. Furthermore, it shows superior methanol tolerance, which is almost immune to methanol poisoning and generates up to 162 mW·cm−2 power density in direct methanol fuel cells.

The search for a low‐cost metal‐free cathode material with excellent mass transfer structure and catalytic activity in oxygen reduction reaction (ORR) is one of the most challenging issues in fuel cells. In this work, nitrogen‐rich m‐phenylenediamine is introduced into the synthesis of porous carbon spheres to tune the pore structure and nitrogen‐doped active sites. As a result, more pyridinic N and pyrrolic N functional species were observed at the interior and surface of the carbon spheres. The introduction of m‐phenylenediamine also regulated the nucleating of precursors, an urchin‐like mesoporous surface structure ensures point contact and less agglomeration between each particle was obtained. With optimized proportion of micropores/mesopores and improved nitrogen‐contained functional species, the ORR activity can be remarkably improved. The half‐wave potential of this catalyst could achieve to 0.81 V (versus RHE) which is only 42 mV lower than commercial Pt/C catalyst. Furthermore, the optimized cathode catalyst achieved a 69 mW cm−2 maximum power density when operated in direct methanol fuel cells at room temperature.

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ZIF-8-derived Fe–N–S triple doping hollow-shell nanoparticles are prepared by the surface modification of SCN– ligands. Fe3+ ions are highly adsorbed on the SCN–-modified layer, forming a hollow-shell rhombic dodecahedron particle after pyrolysis. Doping extra S atom is found to be an effective method to increase the density of atomically dispersed active sites and boost their catalytic performance. The H-ZIF-Fe-SCN catalyst shows good bifunctional stability toward the oxygen reduction reaction and the oxygen evolution reaction in alkaline solution, the half-wave potential for the H-ZIF-Fe-SCN catalyst was recorded to be 0.889 V vs reverse hydrogen electrode, and a maximum power performance of 158.8 mW cm–2 was achieved when it was used as a cathode catalyst in zinc–air batteries.

Electric-driven CO2 reduction offers a promising strategy for CO2 conversion into valuable chemicals and fuels. However, developing low cost and efficient catalysts is still a challenge. Although earth-abundant Zn with the capability of converting CO2 to CO is considered to be one of the promising materials, the low selectivity and stability of Zn catalyst limit its practical applications in CO2 reduction. Herein, we report a highly selective and stable layer-stacked Zn catalyst prepared by an efficient and facile electrochemical method for CO2 reduction to CO. The layer-stacked Zn can produce CO with more than 90% Faradaic efficiency at an overpotential of 0.9 V. Notably, the layer-stacked Zn maintained ∼90% CO selectivity in CO2 electrolysis for more than 70 h, which significantly surpasses the durability of the reported Zn-based catalysts to date. In addition, after prolonged CO2 reduction, the robust catalytic performance of layer-stacked Zn can be recovered repeatedly by the simple electrochemical method, which may be linked to the maintained layer-stacked structure even after multiple reactivations. Further analysis suggests that while abundant low-coordinated sites (corners and edges) can be created on layer-stacked Zn, the enhanced catalytic performance in CO2 reduction is mainly correlated with the created corners instead of edges, owing to that corners not only improve the intrinsic CO2 reduction activity but also inhibit H2 evolution simultaneously.