Single-atom catalysts (SACs) show great promise in various applications due to their maximal atom utilization efficiency. However, the controlled synthesis of SACs with appropriate porous structures ...remains a challenge that must be overcome to address the diffusion issues in catalysis. Resolving these diffusion issues has become increasingly important because the intrinsic activity of the catalysts is dramatically improved by spatially isolated single-atom sites. Herein, we develop a facile topo-conversion strategy for fabricating hollow mesoporous metal-nitrogen-carbon SACs with enhanced diffusion for catalysis. Several hollow mesoporous metal-nitrogen-carbon SACs, including Co, Ni, Mn and Cu, are successfully fabricated by this strategy. Taking hollow mesoporous cobalt-nitrogen-carbon SACs as a proof-of-concept, diffusion and kinetic experiments demonstrate the enhanced diffusion of hollow mesoporous structures compared to the solid ones, which alleviates the bottleneck of poor mass transport in catalysis, especially involving larger molecules. Impressively, the combination of superior intrinsic activity from Co-N
sites and the enhanced diffusion from the hollow mesoporous nanoarchitecture significantly improves the catalytic performance of the oxidative coupling of aniline and its derivatives.
Composites incorporating metal nanoparticles (MNPs) within metal-organic frameworks (MOFs) have broad applications in many fields. However, the controlled spatial distribution of the MNPs within MOFs ...remains a challenge for addressing key issues in catalysis, for example, the efficiency of catalysts due to the limitation of molecular diffusion within MOF channels. Here we report a facile strategy that enables MNPs to be encapsulated into MOFs with controllable spatial localization by using metal oxide both as support to load MNPs and as a sacrificial template to grow MOFs. This strategy is versatile to a variety of MNPs and MOF crystals. By localizing the encapsulated MNPs closer to the surface of MOFs, the resultant MNPs@MOF composites not only exhibit effective selectivity derived from MOF cavities, but also enhanced catalytic activity due to the spatial regulation of MNPs as close as possible to the MOF surface.
Single‐atom catalysts have drawn considerable attention because of their unique catalytic properties. However, the high surface energy of single atoms restricts their fabrication and creates ...significant challenges for further developments. In order to overcome this problem, metal organic framework (MOF)‐derived carbon materials can be served as ideal supports to anchor atomically dispersed metal atoms, due to their tunable particle size and shape features, by providing high surface area, porosity, thermal, and chemical stability. This review highlights the recent advances in i) different types of construction strategies for MOF‐derived carbon‐supported single‐atom catalysts, and ii) the catalytic applications of these MOF‐derived carbon‐supported single‐atom catalysts. Further, this review offers a valuable insight into the current challenges and future opportunities for MOF‐derived carbon‐supported single‐atom catalysts.
Metal organic framework (MOF)‐derived carbon materials are ideal supports to anchor atomically dispersed metal atoms. This review highlights the recent advances in the construction strategies and catalytic applications of the MOF‐derived carbon‐supported single‐atom catalysts. Further, this review offers a valuable insight into the current challenges and future opportunities in this rapidly ongoing area.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Layered double hydroxides have demonstrated great potential for the oxygen evolution reaction, which is a crucial half-reaction of overall water splitting. However, it remains challenging to apply ...layered double hydroxides in other electrochemical reactions with high efficiency and stability. Herein, we report two-dimensional multifunctional layered double hydroxides derived from metal-organic framework sheet precursors supported by nanoporous gold with high porosity, which exhibit appealing performances toward oxygen/hydrogen evolution reactions, hydrazine oxidation reaction, and overall hydrazine splitting. The as-prepared catalyst only requires an overpotential of 233 mV to reach 10 mA·cm
−2
toward oxygen evolution reaction. The overall hydrazine splitting cell only needs a cell voltage of 0.984 V to deliver 10 mA·cm
−2
, which is far more superior than that of the overall water splitting system (1.849 V). The appealing performances of the catalyst can be contributed to the synergistic effect between the metal components of the layered double hydroxides and the supporting effect of the nanoporous gold substrate, which could endow the sample with high surface area and excellent conductivity, resulting in superior activity and stability.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Guillain–Barré syndrome (GBS) is an acute demyelinating polyneuritis in which the immune system attacks part of the peripheral nervous system. About two-thirds of GBS patients have a history of acute ...infection before developing GBS. Immunotherapy and supportive therapies are widely used to treat GBS; however, one in three patients experiences neurologic sequelae. In China, acupuncture–moxibustion has shown unique benefits for the treatment of neurological diseases and has a wide range of applications in neurology.
We treated an elderly Russian female patient diagnosed with GBS. The chief complaints were upper limb weakness, lower limb paralysis, and inability to self-care. The traditional Chinese medicine diagnosis was flaccidity syndrome (Wei Zheng). After 5 weeks of acupuncture and moxibustion combined with Chinese patent medicine treatment, the patient's limb muscle strength was significantly improved and her ability to self-care was largely restored.
The present findings demonstrated that acupuncture and moxibustion combined with Chinese patent medicine can alleviate muscle weakness caused by GBS. However, clinical randomized controlled trials are warranted to verify the precise clinical efficacy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
B and N co-doped carbon matrix anchored with single atomic Fe sites was fabricated through calcination with ferroceneboronic acid wrapped in ZIF−8. The catalyst exhibits extraordinary ...electrocatalytic activities and stability for both CO2 electroreduction and Zn−CO2 battery.
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•B/N-coordinated single-Fe-atom catalyst is first reported for CO2 reduction.•It achieves a faradic efficiency of nearly 100% at 130 mA cm−2 for CO production.•The assembled Zn − CO2 battery exhibits a maximal power density of 1.18 mW cm−2.•The B-doping favors the *COOH formation and suppresses hydrogen evolution as well.
Electrocatalytic CO2 reduction reaction (CRR), powered by renewable energy sources, is a promising route to address energy and environmental issues. Herein, we fabricate single atomic Fe sites anchored on B and N co-doped carbon (Fe-SA/BNC), which showed excellent CRR activity, achieving a highest Faradaic efficiency of ∼ 94% at −0.7 V versus reversible hydrogen electrode. The performance is much better than that of the B-free sample. Furthermore, an outstanding current density of ∼ 130 mA cm−2, as well as ∼ 99% Faradaic efficiency, has been achieved using the membrane electrode assembly (MEA). Details of density functional theory (DFT) calculations revealed that the introduction of B was beneficial for the desorption of *CO. The Zn-CO2 battery was then assembled, which reached a high peak power density of 1.18 mW cm−2 at a current density of 4 mA cm−2, as well as showing remarkable stability for CO production.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Metal–organic frameworks (MOFs) with uniform porous structures show great promise for size/shape-selective catalysis, but their microsized pores and narrow channels inherently limit the diffusion of ...catalytic substrates and their catalytic efficiency. Herein, we report the fabrication of a hollow mesoporous MOF with hollow macroporous core and mesoporous shell, featuring a hierarchical porous structure that allows fast diffusion of reactants. The hollow core and mesoporous shell of the MOF were achieved by an elaborate design of a bimetallic MOF with stability differences in both metal–ligand bonds and spatial distribution via a boosted nucleation process, followed by selective etching treatment. Impressively, the hollow mesoporous MOF greatly enhanced the mass diffusion within the framework, which is demonstrated by the diffusion experiments, the molecular dynamics simulation, and the catalytic reaction by using 4-chlorostyrene as a probe. In addition, the as-prepared hollow mesoporous MOF exhibited superior catalytic performance when utilized as a Pd nanoparticles carrier, compared with solid Pd/MOF and commercial Pd/C catalysts toward benzyl alcohol oxidation.
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IJS, KILJ, NUK, PNG, UL, UM
Exploiting effective non‐noble metal electrocatalysts for oxygen reduction reaction (ORR) is crucial for fuel cells and metal‐air batteries. Herein, we designed and fabricated Co nanoparticles ...confined in Mo/N co‐doped polyhedral carbon frameworks (Co‐NP/MNCF) derived from polyoxometalate‐encapsuled metal–organic framework, which showed comparable ORR performance with commercial Pt/C and a larger diffusion‐limited current density. Moreover, the Co‐NP/MNCF also exhibited excellent ORR stability and methanol tolerance. These appealing performances can be attributed to the porosity regulation and heteroatom doping of metal–organic framework derived polyhedral carbon frameworks, which could be beneficial for the exposure of more active sites, the optimization of electronic structure and the mass transfer of electrolyte/electron/ion.
In this work, Co nanoparticles were confined in the mesoporous Mo/N co‐doped polyhedral carbon frameworks, which showed enhanced ORR performances due to the formation of mesoporous structures induced by PMo.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
One-dimensional (1D) nanomaterials easily bend due to perturbations from their surroundings or their own behaviors. This phenomenon not only impacts the performances of various devices but has also ...been employed to develop a variety of new functional devices, in which the bending energies of the nanomaterials determine the device performances. However, measuring the energies of such nanomaterials is extremely difficult. Herein, pseudo-break imaging of 1D nanomaterials has been proposed and realized on individual carbon nanotubes (CNTs), in which a CNT appears to break and has a fracture but is actually intact. This imaging approach provides the values of the bending energies of the CNTs with an accuracy of 1–50 eV. Furthermore, this imaging approach can manipulate the bending shapes and energies of CNTs. This work presents a protocol for bending analysis and manipulation, which are vital to fundamental and applied studies of 1D nanomaterials.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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