Iron phthalocyanine (FePc) is a promising non-precious catalyst for the oxygen reduction reaction (ORR). Unfortunately, FePc with plane-symmetric FeN 4 site usually exhibits an unsatisfactory ORR activity due to its poor O 2 adsorption and activation. Here, we report an axial Fe-O coordination induced electronic localization strategy to improve its O 2 adsorption, activation and thus the ORR performance. Theoretical calculations indicate that the Fe-O coordination evokes the electronic localization among the axial direction of O-FeN 4 sites to enhance O 2 adsorption and activation. To realize this speculation, FePc is coordinated with an oxidized carbon. Synchrotron X-ray absorption and Mössbauer spectra validate Fe-O coordination between FePc and carbon. The obtained catalyst exhibits fast kinetics for O 2 adsorption and activation with an ultralow Tafel slope of 27.5 mV dec −1 and a remarkable half-wave potential of 0.90 V. This work offers a new strategy to regulate catalytic sites for better performance.

The photoreduction of CO2 to hydrocarbon products has attracted much attention because it provides an avenue to directly synthesize value‐added carbon‐based fuels and feedstocks using solar energy. Among various photocatalysts, graphitic carbon nitride (g‐C3N4) has emerged as an attractive metal‐free visible‐light photocatalyst due to its advantages of earth‐abundance, nontoxicity, and stability. Unfortunately, its photocatalytic efficiency is seriously limited by charge carriers′ ready recombination and their low reaction dynamics. Modifying the local electronic structure of g‐C3N4 is predicted to be an efficient way to improve the charge transfer and reaction efficiency. Here, boron (B) is doped into the large cavity between adjacent tri‐s‐triazine units via coordination with two‐coordinated N atoms. Theoretical calculations prove that the new electron excitation from N (2px, 2py) to B (2px, 2py) with the same orbital direction in B‐doped g‐C3N4 is much easier than N (2px, 2py) to C 2pz in pure g‐C3N4, and improves the charge transfer and localization, and thus the reaction dynamics. Moreover, B atoms doping changes the adsorption of CO (intermediate), and can act as active sites for CH4 production. As a result, the optimal sample of 1%B/g‐C3N4 exhibits better selectivity for CH4 with ≈32 times higher yield than that of pure g‐C3N4.

Electrochemical production of hydrogen peroxide (H 2 O 2 )t hrough two-electron (2 e À )o xygen reduction reaction (ORR) is an on-site and clean route.O xygen-doped carbon materials with high ORR activity and H 2 O 2 selectivity have been considered as the promising catalysts,h owever,t here is still alackofdirect experimental evidence to identify true active sites at the complex carbon surface.H erein, we propose ac hemicalt itration strategy to decipher the oxygen-doped carbon nanosheet (OCNS 900 )c atalyst for 2e À ORR. The OCNS 900 exhibits outstanding 2e À ORR performances with onset potential of 0.825 V( vs.R HE), mass activity of 14.5 Ag À1 at 0.75 V( vs.R HE) and H 2 O 2 production rate of 770 mmol g À1 h À1 in flow cell, surpassing most reported carbon catalysts.Through selective chemical titration of C = O, C À OH, and COOH groups,wefound that C = Ospecies contributed to the most electrocatalytic activity and were the most active sites for 2e À ORR, which were corroborated by theoretical calculations.

Electrochemical CO 2 reduction is a promising way to mitigate CO 2 emissions and close the anthropogenic carbon cycle. Among products from CO 2 RR, multicarbon chemicals, such as ethylene and ethanol with high energy density, are more valuable. However, the selectivity and reaction rate of C 2 production are unsatisfactory due to the sluggish thermodynamics and kinetics of C−C coupling. The electric field and thermal field have been studied and utilized to promote catalytic reactions, as they can regulate the thermodynamic and kinetic barriers of reactions. Either raising the potential or heating the electrolyte can enhance C−C coupling, but these come at the cost of increasing side reactions, such as the hydrogen evolution reaction. Here, we present a generic strategy to enhance the local electric field and temperature simultaneously and dramatically improve the electric−thermal synergy desired in electrocatalysis. A conformal coating of ∼5 nm of polytetrafluoroethylene significantly improves the catalytic ability of copper nanoneedles (∼7-fold electric field and ∼40 K temperature enhancement at the tips compared with bare copper nanoneedles experimentally), resulting in an improved C 2 Faradaic efficiency of over 86% at a partial current density of more than 250 mA cm −2 and a record-high C 2 turnover frequency of 11.5 ± 0.3 s −1 Cu site −1 . Combined with its low cost and scalability, the electric−thermal strategy for a state-of-the-art catalyst not only offers new insight into improving activity and selectivity of value-added C 2 products as we demonstrated but also inspires advances in efficiency and/or selectivity of other valuable electro-/photocatalysis such as hydrogen evolution, nitrogen reduction, and hydrogen peroxide electrosynthesis.

Atomically dispersed transition metal sites have been extensively studied for CO 2 electroreduction reaction (CO 2 RR) to CO due to their robust CO 2 activation ability. However, the strong hybridization between directionally localized d orbits and CO vastly limits CO desorption and thus the activities of atomically dispersed transition metal sites. In contrast, s-block metal sites possess nondirectionally delocalized 3s orbits and hence weak CO adsorption ability, providing a promising way to solve the suffered CO desorption issue. Herein, we constructed atomically dispersed magnesium atoms embedded in graphitic carbon nitride (Mg-C 3 N 4 ) through a facile heat treatment for CO 2 RR. Theoretical calculations show that the CO desorption on Mg sites is easier than that on Fe and Co sites. This theoretical prediction is demonstrated by experimental CO temperature program desorption and in situ attenuated total reflection infrared spectroscopy. As a result, Mg-C 3 N 4 exhibits a high turnover frequency of % 18 000 per hour in H-cell and a large current density of À300 mA cm À2 in flow cell, under a high CO Faradaic efficiency ! 90 % in KHCO 3 electrolyte. This work sheds a new light on s-block metal sites for efficient CO 2 RR to CO.