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Herein, a novel strategy has been proposed to design a hollow structure via post-modified N sites coordinating to metal species. As a result, an atomically dispersed Co site catalyst with high loading has been obtained and has shown superb performance in CO2 cycloaddition to ethylene carbonate. This novel avenue can be extended to other atomically dispersed metal catalysts with high loading. [ABSTRACT FROM AUTHOR]

Electroreduction of CO2 into valuable fuels and feedstocks offers a promising way for CO2 utilization. However, the commercialization is limited by the low productivity. Here, we report a strategy to enhance the productivity of CO2 electroreduction by improving diffusion of CO2 to the surface of catalysts using porous organic cages (POCs) as an additive. It was noted that the Faradaic efficiency (FE) of C2+ products could reach 76.1 % with a current density of 1.7 A cm−2 when Cu‐nanorod(nr)/CC3 (one of the POCs) was used, which were much higher than that using Cu‐nr. Detailed studies demonstrated that the hydrophobic pores of CC3 can adsorb a large amount of CO2 for the reaction, and the diffusion of CO2 in the CC3 to the nanocatalyst surface is easier than that in the liquid electrolyte. Thus, more CO2 molecules make contact with the nanocatalysts in the presence of CC3, enhancing CO2 reduction and inhibiting generation of H2. [ABSTRACT FROM AUTHOR]

Efficient electroreduction of CO2 into CO and other chemicals turns greenhouse gases into fuels and value-added chemicals, holding great promise for a closed carbon cycle and the alleviation of climate changes. However, there are still challenges in the large-scale application of CO2 electroreduction due to the sluggish kinetics. Herein we develop a self-assembly strategy to synthesize a highly efficient CO2 reduction electrocatalyst with atomically dispersed Ni-N4 active centers anchored on polymer-derived mesh-like N-doped carbon nanofibers (Ni-N4/NC). The Ni-N4/NC exhibits high selectivity for CO2 reduction reaction with CO Faradaic efficiency (CO FE) above 90% over a wide potential range from −0.6 to −1.0 V vs. RHE. The catalyst reaches a maximum CO FE up to 98.4% at −0.8 V with a TOF of 1.28 × 105 h−1 and Tafel slope of 113 mV·dec−1. The catalyst also exhibits remarkable stability, with little change in current density and CO FE over a 10-hour durability test at −0.8 V vs. RHE. This method provides a new route for the synthesis of highly efficient CO2 reduction electrocatalyst. [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SACs) regulated by heteroatoms have displayed great potential as electrocatalysts for highly efficient hydrogen evolution reaction (HER); however, the controllable synthesis of an axial coordination structure of SACs to achieve robust HER performance remains a great challenge. Herein, we have proposed a doping-adsorption-pyrolysis strategy to construct NiN4–Cl active sites with axial Cl coordination for accelerating electrocatalytic HER. The obtained NiN4–Cl SAs/NC catalyst exhibits superior HER activity with low over-potential, small Tafel slope, high turnover frequency, and long-term stability. Density functional theory calculation reveals that the excellent HER performance of NiN4–Cl SAs/NC originates from the axial Cl-coordination-induced electronic localization enhancement, which is beneficial for the adsorption and activation of H* intermediate, thus accelerating the HER process. This work opens a new opportunity for rational design and construction of high-performance SAC catalysts by axial coordination strategy for electrocatalytic application. [ABSTRACT FROM AUTHOR]

In the field of electrolysis of water, the design and synthesis of catalysts over a wide pH range have attracted extensive attentions. In this paper, Co and N are co-introduced into the structural unit of tungsten disulfide (WS2), and the hydrogen evolution reaction (HER) performances of different WS2-based catalysts are theoretically predicted and systematically studied by density functional theory (DFT) calculations. With the guidance of DFT calculations, an evaporation-pyrolysis strategy is applied to prepare Co and N co-doped WS2 (Co,N-WS2) flower-like nanosheets, which exhibits excellent HER performance over a wide pH range. In addition, the DFT calculations show that the active sites in Co,N-WS2 have a good ability of hydrogen adsorption after the introduction of Co and N, suggesting that such a co-doping system will be an ideal catalyst for oxidative dehydrogenation (ODH). The following experiment results indeed evidence that the Co,N-WS2 catalyst displays a high activity in the ODH of 1,2,3,4-tetrahydroquinoline (4H-quinoline) and its derivatives. Therefore, this work provides a good example for the rational design and accurate preparation of functional catalysts, which enables it possible to develop other efficient catalysts with multiple functions. [ABSTRACT FROM AUTHOR]

Electrocatalytic reduction of CO2 (CO2RR) to value‐added chemicals is of great significance for CO2 utilization, however the CO2RR process involving multi‐electron and proton transfer is greatly limited by poor selectivity and low yield. Herein, We have developed an atomically dispersed monovalent zinc catalyst anchored on nitrogenated carbon nanosheets (Zn/NC NSs). Benefiting from the unique coordination environment and atomic dispersion, the Zn/NC NSs exhibit a superior CO2RR performance, featuring a high current density up to 50 mA cm−2 with an outstanding CO Faradaic efficiency of ≈95 %. The center ZnI atom coordinated with three N atoms and one N atom that bridges over two adjacent graphitic edges (Zn‐N3+1) is identified as the catalytically active site. Experimental results reveal that the twisted Zn‐N3+1 structure accelerates CO2 activation and protonation in the rate‐determining step of *CO2 to *COOH, while theoretical calculations elucidate that atomically dispersed Zn‐N3+1 moieties decrease the potential barriers for intermediate COOH* formation, promoting the proton‐coupled CO2RR kinetics and boosting the overall catalytic performance. [ABSTRACT FROM AUTHOR]

Using renewable electricity to drive CO2 electroreduction is an attractive way to achieve carbon‐neutral energy cycle and produce value‐added chemicals and fuels. As an important platform molecule and clean fuel, methanol requires 6‐electron transfer in the process of CO2 reduction. Currently, CO2 electroreduction to methanol suffers from poor efficiency and low selectivity. Herein, we report the first work to design atomically dispersed Sn site anchored on defective CuO catalysts for CO2 electroreduction to methanol. It exhibits high methanol Faradaic efficiency (FE) of 88.6 % with a current density of 67.0 mA cm−2 and remarkable stability in a H‐cell, which is the highest FE(methanol) with such high current density compared with the results reported to date. The atomic Sn site, adjacent oxygen vacancy and CuO support cooperate very well, leading to higher double‐layer capacitance, larger CO2 adsorption capacity and lower interfacial charge transfer resistance. Operando experiments and density functional theory calculations demonstrate that the catalyst is beneficial for CO2 activation via decreasing the energy barrier of *COOH dissociation to form *CO. The obtained key intermediate *CO is then bound to the Cu species for further reduction, leading to high selectivity toward methanol. [ABSTRACT FROM AUTHOR]

Guided by first‐principles calculations, it was found that Cd single‐atom catalysts (SACs) have excellent performance in activating CO2, and the introduction of axial coordination structure to Cd SACs cannot only further decrease the free energy barrier of CO2 reduction, but also suppress the hydrogen evolution reaction (HER). Based on the above discovery, we designed and synthesized a novel Cd SAC that comprises an optimized CdN4S1 moiety incorporated in a carbon matrix. It was shown that the catalyst exhibited outstanding performance in CO2 electroreduction to CO. The faradaic efficiency (FE) of CO could reach up to 99.7 % with a current density of 182.2 mA cm−2 in a H‐type electrolysis cell, and the turnover frequency (TOF) value could achieve 73000 h−1, which was much higher than that reported to date. This work shows a successful example of how to design highly efficient catalysts guided by theoretical calculations. [ABSTRACT FROM AUTHOR]

Effecting the synergistic function of single metal atom sites and their supports is of great importance to achieve high-performance catalysts. Herein, we successfully fabricate polyoxometalates (POMs)-stabilized atomically dispersed platinum sites by employing three-dimensional metal-organic frameworks (MOFs) as the finite spatial skeleton to govern the accessible quantity, spatial dispersion, and mobility of metal precursors around each POM unit. The isolated single platinum atoms (Pt1) are steadily anchored in the square-planar sites on the surface of monodispersed Keggin-type phosphomolybdic acid (PMo) in the cavities of various MOFs, including MIL-101, HKUST-1, and ZIF-67. In contrast, either the absence of POMs or MOFs yielded only platinum nanoparticles. Pt1-PMo@MIL-101 are seven times more active than the corresponding nanoparticles in the diboration of phenylacetylene, which can be attributed to the synergistic effect of the preconcentration of organic reaction substrates by porous MOFs skeleton and the decreased desorption energy of products on isolated Pt atom sites. It is of great significance to exert the synergistic effect between single atom and support. Here, the authors prepare polyoxometalates-stabilized single-atom site catalysts in confined space with enhanced activity for alkynes diboration. [ABSTRACT FROM AUTHOR]