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Binary single‐atom catalysts (BSACs) have demonstrated fascinating activities compared to single atom catalysts (SACs) for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Notably, Fe SACs is one of the most promising ORR electrocatalysts, and further revealing the synergistic effects between Fe and other 3d transition metals (M) for FeM BSACs are very important to enhance bifunctional performance. Herein, density functional theory (DFT) calculations are first adapted to demonstrate the role of various transition metals on the bifunctional activity of Fe sites, and a notable volcano relationship is established through the generally accepted adsorption free energy that ΔG*OH for ORR, and ΔG*O−ΔG*OH for OER, respectively. Further, ten of the atomically dispersed FeM anchored on nitrogen‐carbon support (FeM‐NC) are successfully synthesized with typical atomic dispersion by a facile movable type printing method. The experimental data confirms the bifunctional activity diversity of FeM‐NC between the early‐ and late‐ transition metals, agrees very well with the DFT results. More importantly, the optimal FeCu‐NC shows the expected performance with high ORR and OER activity, thereby, the assembled rechargeable zinc–air battery delivers a high power density of 231 mW cm−2, and an impressive stability that can be stably operated over 300 h. [ABSTRACT FROM AUTHOR]

Ru-modified monolayer-dispersed WO x /CeO 2 hybrid composites were prepared by co-impregnation (CI) and step impregnation (SI) methods, and the effects of active site distribution on the catalytic oxidation of 1,2-dichloroethane (DCE) were investigated. Ru species tends to be deposited on the monolayer-dispersed WO x (m-WO x) by SI method, which can increase the oxygen vacancies (O V,m-WOx) at m-WO x /CeO 2 interfaces. Abundant O V,m-WOx can promote the formation of more active W–OH and accelerate the dechloridation and oxydehydrogenation of DCE. Oppositely, for CI method, Ru species exists mainly in the form of Ru−O−Ce bonds, increasing the oxygen vacancies (O V,RuCe) into CeO 2 surface lattices and promoting the deep oxidation of intermediate products. The closer contact between the two hetero-interfacial oxygen vacancies (O V,RuCe and O V,m-WOx) on Ru-modified m-WO x /CeO 2 produces a stronger synergistic effect on DCE activation and oxidation, and meanwhile advantageously inhibits the adsorption of chlorine species as well as the formation of polychlorinated by-products. [Display omitted] • Impregnation sequence affects active site distribution on Ru-modified m-WO x /CeO 2 catalysts. • Ru species on m-WO x surfaces increases O V,m-WOx and W–OH by SI method. • CI method generates more Ru−O−Ce and O V,RuCe. • Synergies of hetero-interfacial O V promote DCE activation/oxidation and inhibit Cl species absorption. [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]

The direct methane (CH 4) oxidation to high value-added C1 chemicals is a great promising strategy to explore the CH 4 resource utilization. However, the low activity and selectivity of catalytic performance remains a great conundrum due to the difficulty to activate the C H bond and the unmanageable over oxidation. Herein, Pd x Au y nanowires (NWs) with various Pd/Au atomic ratios are presented as ideal models to explore the atomic-level effect of PdAu atoms for the direct CH 4 oxidation. The influence of reaction parameters are systematically investigated, and Pd 9 Au 1 NWs display a maximum yield of 2890.3 μmol g−1 h−1 with 99% selectivity for the liquid C1 oxygenated products. This enhanced performance is attributed to the combination of one-dimensional structure and the synergistic effect from the suitable portion of Au on Pd sites, which regulates bond strength between adsorbed radicals (•OH, •OOH, •CH 3) and PdAu atoms, confirmed by the density function theory calculations. [Display omitted] • High quality Pd x Au y NWs with different Pd/Au atomic ratios are prepared by galvanic replacement reaction. • The Pd 9 Au 1 NWs show a maximum yield of 2890.3 μmol g-1 h-1 and a 99% selectivity for liquid C1 products. • The incorporation of Au moderates binding strength of intermediates, facilitating the C-H activation. [ABSTRACT FROM AUTHOR]