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Mesoporous nitrogen-doped carbon-anchored single atom Zn was synthesized through etching of ZIF-8 with 1,10-phenanthroline and subsequent pyrolysis based on the Kirkendall effect. The abundant pores and increased surface area promote CO2 adsorption and mass transfer, thus significantly improving the catalytic activity in solvent-free cycloaddition of epoxides with CO2. [ABSTRACT FROM AUTHOR]

The rational design and construction of efficient and inexpensive bifunctional oxygen electrocatalysts are highly desirable for the development of rechargeable Zn–air batteries (ZABs). Although single‐atom Fe sites anchored on N‐doped carbon catalysts (Fe1/NC) ensure high oxygen reduction reaction activity, their unitary atomically dispersed active center faces difficult condition in catalyzing oxygen evolution reaction simultaneously. Herein, a composite catalyst containing heterointerface between Fe1/NC and selenides ((Fe,Co)Se2) is constructed. The obtained (Fe,Co)Se2@Fe1/NC exhibits extremely narrow potential gap of 0.616 V and remarkable stability in alkaline media, outperforming the benchmark catalysts (Pt/C+RuO2: 0.720 V). Experimental results and density functional theory calculations reveal that heterointerface between Fe1/NC and (Fe,Co)Se2 accelerates the electron transfer and provides more moderate adsorption sites, which endow (Fe,Co)Se2@Fe1/NC with extremely high bifunctional oxygen catalytic activity. This study not only provides a superior bifunctional catalyst for ZABs, but also enriches the application of single‐atom catalysts in multifunctional energy storage and conversion devices. [ABSTRACT FROM AUTHOR]

Constructing electrocatalysts with p‐block elements is generally considered rather challenging owing to their closed d shells. Here for the first time, we present a p‐block‐element bismuth‐based (Bi‐based) catalyst with the co‐existence of single‐atomic Bi sites coordinated with oxygen (O) and sulfur (S) atoms and Bi nanoclusters (Biclu) (collectively denoted as BiOSSA/Biclu) for the highly selective oxygen reduction reaction (ORR) into hydrogen peroxide (H2O2). As a result, BiOSSA/Biclu gives a high H2O2 selectivity of 95 % in rotating ring‐disk electrode, and a large current density of 36 mA cm−2 at 0.15 V vs. RHE, a considerable H2O2 yield of 11.5 mg cm−2 h−1 with high H2O2 Faraday efficiency of ~90 % at 0.3 V vs. RHE and a long‐term durability of ~22 h in H‐cell test. Interestingly, the experimental data on site poisoning and theoretical calculations both revealed that, for BiOSSA/Biclu, the catalytic active sites are on the Bi clusters, which are further activated by the atomically dispersed Bi coordinated with O and S atoms. This work demonstrates a new synergistic tandem strategy for advanced p‐block‐element Bi catalysts featuring atomic‐level catalytic sites, and the great potential of rational material design for constructing highly active electrocatalysts based on p‐block metals. [ABSTRACT FROM AUTHOR]

Regulating the coordination environment of transition-metal based materials in the axial direction with heteroatoms has shown great potential in boosting the oxygen reduction reaction (ORR). The coordination configuration and the regulation method are pivotal and elusive. Here, we report a combined strategy of matrix-activization and controlled-induction to modify the CoN4 site by axial coordination of Co—S (Co1N4-S1), which was validated by the aberration-corrected electron microscopy and X-ray absorption fine structure analysis. The optimal Co1N4-S1 exhibits an excellent alkaline ORR activity, according to the half-wave potential (0.897 V vs. reversible hydrogen electrode (RHE)), Tafel slope (24.67 mV/dec), and kinetic current density. Moreover, the Co1N4-S1 based Zn-air battery displays a high power density of 187.55 mW/cm2 and an outstanding charge—discharge cycling stability for 160 h, demonstrating the promising application potential. Theoretical calculations indicate that the better regulation of CoN4 on electronic structure and thus the highly efficient ORR performance can be achieved by axial Co—S. [ABSTRACT FROM AUTHOR]

For electrocatalysts for the hydrogen evolution reaction (HER), encapsulating transition metal phosphides (TMPs) into nitrogen‐doped carbon materials has been known as an effective strategy to elevate the activity and stability. Yet still, it remains unclear how the TMPs work synergistically with the N‐doped support, and which N configuration (pyridinic N, pyrrolic N, or graphitic N) contributes predominantly to the synergy. Here we present a HER electrocatalyst (denoted as MoP@NCHSs) comprising MoP nanoparticles encapsulated in N‐doped carbon hollow spheres, which displays excellent activity and stability for HER in alkaline media. Results of experimental investigations and theoretical calculations indicate that the synergy between MoP and the pyridinic N can most effectively promote the HER in alkaline media. [ABSTRACT FROM AUTHOR]

We developed a strategy based on coordination polymer to synthesize singleatom site Fe/N and S-codoped hierarchical porous carbon (Fe1/N,S-PC). The as-obtained Fe1/N,S-PC exhibited superior oxygen reduction reaction (ORR) performance with a half-wave potential (E1/2, 0.904 V vs. RHE) that was better than that of commercial Pt/C (E1/2, 0.86 V vs. RHE), single-atom site Fe/N-doped hierarchical porous carbon (Fe1/N-PC) without S-doped (E1/2, 0.85 V vs. RHE), and many other nonprecious metal catalysts in alkaline medium. Moreover, the Fe1/N,S-PC revealed high methanol tolerance and firm stability. The excellent electrocatalytic activity of Fe1/N,S-PC is attributed to the synergistic effects from the atomically dispersed porphyrin-like Fe-N4 active sites, the heteroatom codoping (N and S), and the hierarchical porous structure in the carbon materials. The calculation based on density functional theory further indicates that the catalytic performance of Fe1/N,S-PC is better than that of Fe1/N-PC owing to the sulfur doping that yielded different rate-determining steps. [ABSTRACT FROM AUTHOR]

Supported Cu single-atom (Cu-SA) catalysts have exhibited unique activity and selectivity in CO 2 reduction, but they generally suffer from the easy transformation of active Cuδ+ into inactive Cu0. Herein, porous TiO 2 supported Cu single atoms (Cu-SAs/TiO 2) photocatalyst was fabricated and dioxygen (O 2) enhanced photocatalytic CO 2 reduction performance of Cu-SAs/TiO 2 was investigated by in-situ characterizations and theoretical calculations. The results showed that both activity and stability of Cu-SAs/TiO 2 photocatalyst could be improved by feeding a small amount of O 2 (117.6 ppm) in the reaction system. The competitive electron transfer to O 2 on Cu-SAs/TiO 2 maintained dynamic stability of Cuδ+ active sites, and O 2 -derived *OOH species lowered the formation energy barrier of key intermediate *COOH as well as delivered *H species for accelerating intermediates protonation process. Total yield rate of CH 4 and CO reached 34.64 μmol·g cat ·h−1 for CO 2 photoreduction over Cu-SAs/TiO 2 after introducing 117.6 ppm O 2 , accompanied by enhanced durability. [Display omitted] • Porous TiO 2 supported Cu single atoms (Cu-SAs/TiO 2) photocatalyst was fabricated. • Cu single-atom sites can significantly improve CO 2 photoreduction performance. • The dynamic stability of Cuδ+ sites is sustained by O 2 for photocatalytic CO 2 reduction. • The roles of O 2 are unraveled by in-situ characterizations and DFT calculations. [ABSTRACT FROM AUTHOR]

A hard-magnet L 1 0 -ordered PtFe-alloy nanopillar film (L 1 0 -PtFe NF) is employed as a model catalyst to evaluate its magnetic effect on ORR performance. A magneto-enhancement in ORR catalysis is demonstrated for magnetized L 1 0 -PtFe(M) NF, compared with original L 1 0 -PtFe NF. The chemisorbed oxygen on catalyst surface, especially the primary Pt d yz –O 2 π* coupling, manipulated by the magnetic effect plays the key role in the catalysis optimization. • A fully L 1 0 -ordered PtFe nanopillar film was engineered as the model catalyst. • The magnetic effect within L 1 0 -PtFe substantially regulates the ORR performance. • The coverage of oxygen on Pt, substantially the primary Pt d yz –O 2 π* coupling, is manipulated by the magnetic effect. • It paves the way for the implementation of magnetic effect towards broad catalysis. It is important to improve the oxygen reduction reaction (ORR) performance of Pt by alloying it with first-row transition metals (M: e.g., Fe, Co, Ni). It is known that the ligand, strain, and ensemble effects govern the ORR performance. However, the intrinsic magnetic characteristics of PtMs have rarely been focused on in ORR investigations. Here, we employed a hard-magnet L 1 0 -ordered PtFe nanopillar film (L 1 0 -PtFe NF) as model catalyst to uncover the catalyst's magnetic effect on the ORR. We report a five-fold enhancement of the catalytic efficiency of magnetized L 1 0 -PtFe(M) NF compared with unmagnetized one. Further investigations demonstrate that the coverage of chemisorbed oxygen on catalyst surface, especially the primary Pt d yz –O 2 π* coupling, manipulated by the catalyst's magnetic field is the key factor for the ORR regulation. This work thus paves the way for the implementation of magnetic effect towards the precise regulation in broad catalysis applications. [ABSTRACT FROM AUTHOR]