The electrochemical synthesis of chemicals from carbon dioxide, which is an easily available and renewable carbon resource, is of great importance. However, to achieve high product selectivity for ...desirable C2 products like ethylene is a big challenge. Here we design Cu nanosheets with nanoscaled defects (2–14 nm) for the electrochemical production of ethylene from carbon dioxide. A high ethylene Faradaic efficiency of 83.2% is achieved. It is proved that the nanoscaled defects can enrich the reaction intermediates and hydroxyl ions on the electrocatalyst, thus promoting C–C coupling for ethylene formation.
Developing highly efficient electrocatalysts based on cheap and earth-abundant metals for CO
reduction is of great importance. Here we demonstrate that the electrocatalytic activity of ...manganese-based heterogeneous catalyst can be significantly improved through halogen and nitrogen dual-coordination to modulate the electronic structure of manganese atom. Such an electrocatalyst for CO
reduction exhibits a maximum CO faradaic efficiency of 97% and high current density of ~10 mA cm
at a low overpotential of 0.49 V. Moreover, the turnover frequency can reach 38347 h
at overpotential of 0.49 V, which is the highest among the reported heterogeneous electrocatalysts for CO
reduction. In situ X-ray absorption experiment and density-functional theory calculation reveal the modified electronic structure of the active manganese site, on which the free energy barrier for intermediate formation is greatly reduced, thus resulting in a great improvement of CO
reduction performance.
To develop photocatalysts with desirable compositions and structures for improving the efficiency and selectivity of CO2 conversion to CH4 under mild conditions is of great importance. Here, we ...design an effective photocatalyst of bimetal (Ag/Pd) nanoalloys supported on nitrogen-doped TiO2 nanosheet for CO2 conversion. Such a novel photocatalyst combines multiple advantages of abundant Ti3+ ions, oxygen vacancies, and substitutional nitrogen that are favorable for catalyzing CO2 reduction. It was found that CO2 could be efficiently transformed to CH4 under mild conditions, i.e., in aqueous solution and at atmospheric pressure and room temperature. The maximum production rate of CH4 can reach 79.0 μmol g–1 h–1. Moreover, the Ag/Pd bimetals supported on N-doped TiO2 nanosheet exhibit high selectivity to CH4. The as-synthesized photocatalyst can be well recycled for CO2 reduction.
The electroreduction of CO
2
to valuable chemicals and fuels offers an effective mean for energy storage. Although CO
2
has been efficiently converted into C
1
products (e.g., carbon monoxide, formic ...acid, methane and methanol), its convention into high value-added multicarbon hydrocarbons with high selectivity and activity still remains challenging. Here we demonstrate the formation of multi-shelled CuO microboxes for the efficient and selective electrocatalytic CO
2
reduction to C
2
H
4
. Such a structure favors the accessibility of catalytically active sites, improves adsorption of reaction intermediate (CO), inhibits the diffusion of produced OH
−
and promotes C—C coupling reaction. Owing to these unique advantages, the multi-shelled CuO microboxes can effectively convert CO
2
into C
2
H
4
with a maximum faradaic efficiency of 51.3% in 0.1 M K
2
SO
4
. This work provides an effective way to improve CO
2
reduction efficiency via constructing micro- and nanostructures of electrocatalysts.
To construct the heterojunctions of TiO
2
with other compounds is of great importance for overcoming its inherent shortages and improving the visible-light photocatalytic performance. Here we propose ...the construction of TiO
2
/covalent organic framework (COF) heterojunction with tight connection by a supercritical CO
2
(SC CO
2
) method, which helps bridging the transformation paths for photo-induced charge between TiO
2
and COF. The produced TiO
2
/COF heterojunction performs a H
2
evolution of 3,962 µmol·g
−1
·h
−1
under visible-light irradiation, which is ∼ 25 times higher than that of pure TiO
2
and 4.5 folds higher than that of TiO
2
/COF synthesized by the conventional solvothermal method. This study opens up new possibilities for constructing heterojunctions for solar energy utilization.
The application of nickel in electrocatalytic reduction of CO
2
has been largely restricted by side reaction (hydrogen evolution reaction) and catalyst poisoning. Here we report a new strategy to ...improve the electrocatalytic performance of nickel for CO
2
reduction by employing a nitrogen-carbon layer for nickel nanoparticles. Such a nickel electrocatalyst exhibits high Faradaic efficiency 97.5% at relatively low potential of -0.61 V for the conversion of CO
2
to CO. Density functional theory calculation reveals that it is thermodynamically accomplishable for the reduction product CO to be removed from the catalyst surface, thus avoiding catalyst poisoning. Also, the catalyst renders hydrogen evolution reaction to be suppressed and hence reasonably improves catalytic performance.
It is of great importance to develop facile strategies to synthesize catalysts with desirable compositions and structures for high-performance photocatalytic hydrogen generation. In this work, we put ...forward an ionic liquid assisted one-pot route for the synthesis of heteroatom-doped Pt/TiO
2
composite material. This route is simple, environmentally benign and adjustable owing to the designable properties of ionic liquids. The as-synthesized Pt/TiO
2
nanocrystals exhibit high activity and stability for the photocatalytic hydrogen generation under simulated solar irradiation. This method can be easily applied to the synthesis of various kinds of metal/TiO
2
composites doped with desirable heteroatoms (e.g., F, Cl, Br, etc).
UiO-66-NH2, an important metal–organic framework, is usually synthesized by solvothermal method and the particle size is generally larger than 200 nm, which limits its catalytic applications in ...chemical reactions. It is very meaningful to produce UiO-66-NH2 nanoparticles with ultra-small size, but remains challenging. Herein, we synthesized UiO-66-NH2 nanoparticles in size of 8–15 nm that are immobilized on g-C3N4 nanosheets. Compared with the UiO-66-NH2 synthesized by the traditional solvothermal method (> 200 nm), the ultra-small UiO-66-NH2 nanoparticles immobilized on g-C3N4 have more unsaturated coordination positions and increased Lewis acidity. Owing to these combined advantages, the ultra-small UiO-66-NH2 nanoparticles exhibit greatly improved catalytic activity for Meerwein–Ponndorf–Verley reaction than larger UiO-66-NH2 particles.
Herein, we synthesized UiO-66-NH2 nanoparticles in size of 8–15 nm that are immobilized on g-C3N4 nanosheets. Compared with the UiO-66-NH2 micronparticles (~0.2 μm), the ultra-small UiO-66-NH2 nanoparticles exhibit high catalytic activity for Meerwein–Ponndorf–Verley reaction owing to more unsaturated coordination positions and increased Lewis acidity. Display omitted
Zinc–iodine batteries are promising energy storage devices with the unique features of aqueous electrolytes and safer zinc. However, their performances are still limited by the polyiodide shuttle and ...the unclear redox mechanism of iodine species. Herein, a single iron atom was embedded in porous carbon with the atomic bridging structure of metal–nitrogen–carbon to not only enhance the confinement effect but also invoke the electrocatalytic redox conversion of iodine, thereby enabling the large capacity and good cycling stability of the zinc–iodine battery. In addition to the physical trapping effect of porous carbon with good electronic conductivity, the in situ experimental characterization and theoretical calculation reveal that the metal–nitrogen–carbon bridging structure modulates the electronic properties of carbon and adjusts the intrinsic activity for the reversible conversion of iodine via the thermodynamically favorable pathway. This work demonstrates that the physicochemical confinement effect can be invoked by the rational anchoring of a single metal atom with nitrogen in a porous carbon matrix to enhance the electrocatalytic redox conversion of iodine, which is crucial to fabricating high-performing zinc–iodine batteries and beyond by applying the fundamental principles.
To meet strategic applications, electrochemical reduction of CO2 into value‐added chemical molecules would be improved by the rational design of advanced electrocatalysts with atomically dispersed ...active sites. Herein an electrospun‐pyrolysis cooperative strategy is presented to not only modulate the porous structure of the carbon support for favorable charge and mass transfer, but also adjust the bridging structure of atomically dispersed metal species. Typically, the experimental results and theoretical calculations revealed that the unique chemical structure of binuclear nickel bridging with nitrogen and carbon atoms (namely Ni2−N4−C2) tunes the electronic nature of the d‐states for the optimal adsorption of carbon dioxide and intermediates, thus inducing the substantial enhancement of CO2 reduction via the thermodynamically more favorable pathway. The identification of such a structure demonstrates the large space to modulate the atomic bridging status for optimizing electrocatalysis.
The atomic bridging structure of nickel–nitrogen–carbon active sites confined in channel‐rich porous carbon fibers enables the highly efficient electrocatalytic reduction of CO2.
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