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[Display omitted] • hs-CoFe catalyst with "plate reactor" structure was facilely synthesized. • Hetero-porous structure was constructed by selective etching and rGO supporting. • The OER/ORR was lowered to 0.608 V due to this smooth mass transfer channel. • ZAB performance and stability were significantly boosted. Large-scale application of zinc air batteries (ZABs) is impeded by the lack of efficient and cost-effective bifunctional oxygen catalysts. In this work, hetero-porous is rationally engineered for the carbon encapsulated CoFe catalyst, which is highly active toward both oxygen evolution reaction (OER) and oxygen evolution reaction (ORR). The hs-CoFe catalyst with "plate reactor" structure is facilely synthesized by combining the selective etching and reduced graphene oxide supporting to construct pores with size of 10–100 nm and 100–1000 nm, respectively, for smooth mass transfer. OER/ORR activities are significantly boosted, and difference between the potential to deliver 10 mA/cm2 OER and half wave potential of ORR is therefore lowered to 0.608 V while this potential difference of Pt/C-IrO 2 is 0.732 V. The corresponding ZAB exhibits a maximum power density of 232 mW/cm2, which sheds light on providing a novel strategy for oxygen reaction catalyst designation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A general strategy is developed to prepare ternary single-atom catalysts. • The ternary single-atom catalyst shows high bifunctional activity. • Theatrical calculations provide insights into enhanced bifunctional performance. Synergistic effects have been demonstrated for binary single-atom catalysts (SACs), while it is still challenging to investigate the activity and performance of ternary SACs due to the lack of robust method to synthesize these materials. Herein, we provide a general approach for the preparation of ternary SACs, and the features of single atoms highly dispersed on the support have been identified and verified. As an illustration, trace platinum decorated iron-cobalt ternary single atom catalysts (PtFeCo/NC) possess an obviously enhanced bifunctional activity of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), as well as high stability. The density functional theory calculations reveal that the synergistic effects induced by the introduction of Pt enable modulating the adsorption strength of reaction intermediates both on the Fe-N 4 and Co-N 4 sites, thus enhancing the ORR and OER activity, respectively. In addition, the PtFeCo/NC-based Zn-air battery delivers a higher power density than that of commercial Pt/C-RuO 2 , and can be steadily operated over 188 h. [ABSTRACT FROM AUTHOR]

[Display omitted] • A silver decorated amorphous cobalt hydr(oxy)oxide is fabricated through a pre-oxidation process. • The catalyst exhibits outstanding OER performance and excellent stability. • The catalyst ranks amongst the highest OER activity for cobalt-based catalysts of recent studies. • Ag decoration induced greater Co3+ content, higher electrochemically active specific surface area, and better electron conductivity synergistically enhance the catalytic performance. "Soft" and "flexible" amorphous materials have gained traction recently due to their self-adjustability toward environmental changes. Unfortunately, poor conductivity and limited stability seriously hamper their commercial applications. In this work, we develop an Ag-decorated amorphous and efficient oxygen evolution reaction (OER) catalyst, requiring overpotentials of only 170 and 250 mV to yield current densities of 10 and 100 mA cm−2 in a 1.0 M KOH solution, respectively. The catalyst also exhibits outstanding stability, maintaining 93.1% of its initial performance after 27 h of continuous testing. When used as an air-electrode catalyst in a zinc-air battery, it recorded a charge–discharge cycle life of 330 h at a current density of 5 mA cm−2, with a voltage gap of 0.87 V. And the Ag decoration induced better electrical conductivity, more active specific surface, and higher Co3+ content are found to be the proper reasons for the catalyst's outstanding OER performance and stability. [ABSTRACT FROM AUTHOR]