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As a powerful protocol for the preparation of common polymers, such as polyolefins, polyesters, and polycarbonates, late-transition-metal-catalyzed polymerization can be carried out by controlling the reaction conditions or developing dynamic catalytic systems that use external stimuli to influence the performance of the active sites, resulting in well-defined polymeric materials. In particularly, under the latter conditions, 'one catalyst' can provide more than one kind of polymer with a controlled sequence from the monomer mixture, making full use of the prepared catalyst. In this review, tunable modes, including reaction conditions, redox, light or electrochemical properties, Lewis acids, and alkali metal cations, of late-transition-metal-complex (especially iron, cobalt, and nickel)-catalyzed polymerization were collected and thoroughly discussed. [ABSTRACT FROM AUTHOR]

The electrocatalytic carbon dioxide reduction reaction (CO2RR) in an acidic medium is conducive to the efficient utilization of CO2 by preventing the formation of carbonate/bicarbonate. However, acidic media are more favorable for the hydrogen evolution reaction (HER), resulting in unsatisfactory CO2RR selectivities. It is demonstrated that the molecularly dispersed electrocatalyst of β‐tetra methoxy‐substituted nickel phthalocyanine on carbon nanotubes (NiPc‐OMe MDE) can efficiently catalyze CO2RR in acidic media (pH 2 to 0.47) with Faradaic efficiencies of CO >98% over a wide range of current densities from −50 to −400 mA cm−2. It is found that the superior selectivity performance can be attributed to the presence of potassium ions, the high preference of CO2RR over HER on the active site, and few side reaction sites. The study illuminates the potential of molecular electrocatalysts for selective and rapid reduction of CO2 in acid media. [ABSTRACT FROM AUTHOR]

Powered by clean and renewable energy, electrocatalytic CO2 reduction reaction (CO2RR) to chemical feedstocks is an effective way to mitigate the greenhouse effect and artificially close the carbon cycle. However, the performance of electrocatalytic CO2RR was impeded by the strong thermodynamic stability of CO2 molecules and the high susceptibility to hydrogen evolution reaction (HER) in aqueous phase systems. Moreover, the numerous reaction intermediates formed at very near potentials lead to poor selectivity of reaction products, further preventing the industrialization of CO2RR. Catalysis in confined space can enrich the reaction intermediates to improve their coverage at the active site, increase local pH to inhibit HER, and accelerate the mass transfer rate of reactants/products and subsequently facilitate CO2RR performance. Therefore, we summarize the research progress on the application of the confinement effects in the direction of CO2RR in theoretical and experimental directions. We first analyzed the mechanism of the confinement effect. Subsequently, the confinement effect was discussed in various forms, which can be characterized as an abnormal catalytic phenomenon due to the relative limitation of the reaction region. In specific, based on the physical structure of the catalyst, the confinement effect was divided in four categories: pore structure confinement, cavity structure confinement, active center confinement, and other confinement methods. Based on these discussions, we also have summarized the prospects and challenges in this field. This review aims to stimulate greater interests for the development of more efficient confined strategy for CO2RR in the future. [ABSTRACT FROM AUTHOR]

Visible‐light‐responsive bismuth‐based oxyhalide has recently attracted extensive attention, however, the promotion of its charge separation is still challenging. Herein, we introduce iodine into Bi2GdO4Cl to synthetize I‐doped Bi2GdO4Cl (denoted as yI−Bi2GdO4Cl, 0≤y≤2). The incorporation of I− ions is found to enhance light absorption and to accelerate charge separation by combining various characterizations such as density functional theory calculation, photoelectrochemical test, electrochemical impedance spectroscopy, photoluminescence spectrum, and open‐circuit voltage decay. The O2‐evolving performances of 1I−Bi2GdO4Cl with optimized dopant concentration of I− ion and IrO2 loaded 1I−Bi2GdO4Cl are tremendously enhanced by ca. 4 and 45 times compared to pristine Bi2GdO4Cl. Notably, The O2 evolution rate reaches as high as 154.8 μmol ⋅ h−1 with an apparent quantum efficiency of ∼1.1 % at 420 nm. The synthetic iodine‐doped photocatalyst remains stable after long‐term photoreaction, demonstrating its potential in the field of photocatalysis. [ABSTRACT FROM AUTHOR]

Seawater electrolysis is a promising technique for H 2 production on a large scale. However, the electrocatalytic activity and stability will be deteriorated as the increase of salt concentrations which happened in the seawater splitting. Herein, through the electrodeposition and rapid Joule heating method, the Fe-NiO/MoO 2 heterostructure is designed as a highly active bifunctional electrocatalyst. During the OER possess, Fe-NiO/MoO 2 is reconstructed to the Fe, Mo-NiOOH with Fe and Mo co-doping. Based on the theoretical analysis, more electrons were transferred to the O atoms on the surface of Fe, Mo-NiOOH, thereby forming a more negatively charged surface. Moreover, that surface is found to repel Cl− ions while enriching H 2 O molecules to form a thin water layer on Fe, Mo-NiOOH surface based on molecule dynamics (MD) simulation, thereby improving the anti-corrosion capacity of Fe, Mo-NiOOH. The reconstructed Fe, Mo-NiOOH achieved an overpotential of 399 mV at 1000 mA cm−2 in alkaline seawater, and the increase of overpotential for Fe, Mo-NiOOH was about 0.02 V at 500 mA cm−2 from 0 M to 3 M NaCl in 1 M KOH electrolyte. For the HER, Fe-NiO/MoO 2 achieved an overpotential of 169 mV and 417 mV at 100 and 1000 mA cm−2 in alkaline seawater, respectively, and the increase of overpotential for Fe-NiO/MoO 2 was about 0 mV at 500 mA cm−2 from 0 M to 3 M NaCl in 1 M KOH electrolyte. This work sheds fresh light into the development of efficient electrocatalysts for salinity tolerance seawater splitting. [Display omitted] • Negative charges of oxygen atoms on the surface of Fe-NiO/MoO 2 was enhanced by Fe doping. • Fe-NiO/MoO 2 was reconstructed to the Fe, Mo-NiOOH with Fe and Mo co-doping in the OER process. • Chloride ions were repelled away from the negatively charged surface of the Fe, Mo-NiOOH. • Water molecules were enriched on the surface of the Fe, Mo-NiOOH. • Fe, Mo-NiOOH exhibited the high activity, selectivity and stability in the 1 M KOH with high NaCl concentration. [ABSTRACT FROM AUTHOR]

Fundamental understanding of the dynamic behaviors at the electrochemical interface is crucial for electrocatalyst design and optimization. Here, we revisit the oxygen reduction reaction mechanism on a series of transition metal (M = Fe, Co, Ni, Cu) single atom sites embedded in N-doped nanocarbon by ab initio molecular dynamics simulations with explicit solvation. We have identified the dissociative pathways and the thereby emerged solvated hydroxide species for all the proton-coupled electron transfer (PCET) steps at the electrochemical interface. Such hydroxide species can be dynamically confined in a "pseudo-adsorption" state at a few water layers away from the active site and respond to the redox event at the catalytic center in a coupled manner within timescale less than 1 ps. In the PCET steps, the proton species (in form of hydronium in neutral/acidic media or water in alkaline medium) can protonate the pseudo-adsorbed hydroxide without needing to travel to the direct catalyst surface. This, therefore, expands the reactive region beyond the direct catalyst surface, boosting the reaction kinetics via alleviating mass transfer limits. Our work implies that in catalysis the reaction species may not necessarily bind to the catalyst surface but be confined in an active region. The reaction region is commonly considered to be the direct catalyst surface. Here, the authors challenge this view and use molecular dynamics simulations to reveal a solvated hydroxide species dynamically confined in a pseudo-adsorption state at a few water layers away from the active site during oxygen reduction reaction on single atom electrocatalyst. [ABSTRACT FROM AUTHOR]

Developing improved methods for CO2 capture and concentration (CCC) is essential to mitigating the impact of our current emissions and can lead to carbon net negative technologies. Electrochemical approaches for CCC can achieve much higher theoretical efficiencies compared to the thermal methods that have been more commonly pursued. The use of redox carriers, or molecular species that can bind and release CO2 depending on their oxidation state, is an increasingly popular approach as carrier properties can be tailored for different applications. The key requirements for stable and efficient redox carriers are discussed in the context of chemical scaling relationships and operational conditions. Computational and experimental approaches towards developing redox carriers with optimal properties are also described. [ABSTRACT FROM AUTHOR]

The Sabatier activity volcano provides intuitive guide for catalyst design, but also imposes fundamental limitations on the composition and maximal activity of catalysts. We show that the ORR activity volcano is shifted and reshaped by the potential‐dependent fluxionality of subnano cluster catalysts. Fluxionality causes the typically under‐binding Ag/Au to gain optimal activity in the cluster form, and surpass Pt/Pd. Furthermore, isomerization of clusters as a function of the potential breaks linear scaling relationships, enabling surpassing the volcano "apex" relative to the bulk. The effect is likely general for fluxional cluster catalysts. [ABSTRACT FROM AUTHOR]