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Fe single‐atom catalysts (SACs) are a promising catalyst for oxygen reduction reaction (ORR) in both Zn–air batteries (ZABs) but have a certain distance to compete with Pt‐based catalysts. Rational modulation of the coordination environment in the second coordination shell of SACs offers an opportunity to improve the intrinsic ORR activity, yet a challenge. Here, a novel strategy is reported to construct a dual‐metal catalyst by introducing a single Co atom in the second coordination shell of the Fe center. The dual‐metal N3─Fe─N─Co site with a certain Fe─Co distance of 0.312 nm is constructed. It allows for manipulation of the positive shift of the Fe center charge state, driving the d‐band center up‐shift by 0.63 eV, thereby offering the optimal adsorption of intermediates. Benefiting from this structure, the as‐prepared Fe(Co2nd)‐NC enables an excellent ORR activity with a half‐wave potential of 0.948 V in 0.1 M KOH. As a cathode in ZABs, it delivered an outstanding peak power density of 218 mW cm−2 and a specific capacity of 915 mAh gZn−1 at 5 mA cm−2, respectively, with superior long‐term durability over 680 h. The second shell layer alignment regulation strategy shows great potential for energy storage applications. [ABSTRACT FROM AUTHOR]

Fast surface dynamic processes of thiocyanate adsorbed on a nanostructured Pt microelectrode were studied by in situ step-scan time-resolved microscope FTIR spectroscopy ( in situ SSTR-MFTIRS) at a time resolution of 100 μs. It was found that SCN adsorbs preferentially on Pt surface through N atom at low potential, while through S atom at high potential. The potential-induced orientation conversion between N- and S-bounded forms is very reversible, and occurs only within 2 ms after potential alternation. However, the rate constant (4×10 s) of conversion from N- to S-bounded adsorption is nearly double to that of the reverse process (2×10 s). The difference in kinetics of two processes may be explained through the hard-soft acid-base principle. [ABSTRACT FROM AUTHOR]

Adsorption and oxidation of ethylene glycol (EG) on Pt(100) electrode were studied by in situ time-resolved FTIRS (TRFTIRS). The TRFTIR spectra recorded at 0.10 V illustrate that an IR band appears near 2050 cm-1 at t » 5 s, corresponding to linearly bonded CO formed in dissociative adsorption of EG. The TRFTIR results have confirmed also that CO species are distributed uniformly on Pt(100) surface. Another band appears near 2342 cm-1 at t » 70 s, associating with IR absorption of CO2 produced in the direct oxidation of EG. With the increase of electrode potential, the direct oxidation of EG becomes gradually the main reaction. When the potential is above 0.40 V, the oxidation of EG occurs mainly via the reactive intermediates, i.e. species containing -COOH determined by in situ TRFTIRS. [ABSTRACT FROM AUTHOR]

Surface chemical structure of catalyst is found to affect adsorption configurations of CO to control CO 2 reduction pathways. CO adsorption studies show that the bridge-adsorbed CO (CO B) on low-coordination Cu0 site is apt to be hydrogenated to CH 4 , and the bridge-adsorbed CO plus linear-adsorbed CO (CO B + CO L) on local Cu0/Cu+ site are apt to be coupled to C 2 H 4. Among all CO 2 electroreduction products, methane (CH 4) and ethylene (C 2 H 4) are two typical and valuable hydrocarbon products which are formed in two different pathways: hydrogenation and dimerization reactions of the same CO intermediate. Theoretical studies show that the adsorption configurations of CO intermediate determine the reaction pathways towards CH 4 /C 2 H 4. However, it is challenging to experimentally control the CO adsorption configurations at the catalyst surface, and thus the hydrocarbon selectivity is still limited. Herein, we seek to synthesize two well-defined copper nanocatalysts with controllable surface structures. The two model catalysts exhibit a high hydrocarbon selectivity toward either CH 4 (83%) or C 2 H 4 (93%) under identical reduction conditions. Scanning transmission electron microscopy and X-ray absorption spectroscopy characterizations reveal the low-coordination Cu0 sites and local Cu0/Cu+ sites of the two catalysts, respectively. CO-temperature programed desorption, in - situ attenuated total reflection Fourier transform infrared spectroscopy and density functional theory studies unveil that the bridge-adsorbed CO (CO B) on the low-coordination Cu0 sites is apt to be hydrogenated to CH 4 , whereas the bridge-adsorbed CO plus linear-adsorbed CO (CO B + CO L) on the local Cu0/Cu+ sites are apt to be coupled to C 2 H 4. Our findings pave a new way to design catalysts with controllable CO adsorption configurations for high hydrocarbon product selectivity. [ABSTRACT FROM AUTHOR]