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.
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.
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 4chlorostyrene 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.
The fabrication of Zn‐CO2 batteries is a promising technique for CO2 fixation and energy storage. Herein, nitrogen‐doped ordered mesoporous carbon (NOMC) is adopted as a bifunctional metal‐free electrocatalyst for CO2 reduction and oxygen evolution reaction in the near‐neutral electrolyte. The ordered mesoporous structures and abundant N‐dopings of NOMC facilitate the accessibility and utilization of the active sites, which endow NOMC with excellent electrocatalysis performance and outstanding stability. Especially, a nearly 100% CO Faradaic efficiency is achieved at an ultralow overpotential of 360 mV for CO2 reduction. When constructed as an aqueous rechargeable Zn‐CO2 battery using NOMC as the cathode, it yields a high peak power density of 0.71 mW cm−2, a good cyclability of 300 cycles, and excellent energy efficiency of 52.8% at 1.0 mA cm−2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.