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.

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electrical conductivity of the MOF NSs limit their electrocatalytic activity far from practical applications. In addition, timeconsuming coating procedures are always needed to attach powdered MOF NSs onto the surface of the electrode with the assistance of polymeric binders, which may decrease their original activity and cause mechanical stability problems.To address these issues, one effective and feasible way is directly growing the ultrathin BMNSs on self-supported 3D macroporous conductive substrates. In this kind of hierarchical structure, first, the oriented and close arrangement of the ultrathin MOF NSs can avoid the restacking and guarantee the fully exposed electroactive sites. Second, the hierarchical pore structure of the electrode can not only enhance the mass transfer but also facilitate bubble dissipating in gas-generated reactions. [8] Moreover, the close and strong binding of ultrathin MOF NSs with the underlying conductive support gains more efficient electron transfer between them and guarantees the ultrahigh structural stability of the electrodes. [5a,9] However, until now, the controllable growth of different ultrathin BMNSs on various conductive substrates, especially the chemical inert substrates (such as carbon cloth (CC) and carbon fiber paper (CFP)), still remains a challenge because there are only few nucleation sites on the substrates and MOFs tend to form bulk crystals under conventional synthetic conditions. [10] Therefore, it is of great significance to develop a general and effective synthesis strategy to directly grow different ultrathin BMNSs on various conductive substrates to accelerate the practical application of MOFs in electrocatalysis.Herein, we report a general strategy to synthesize various ultrathin BMNSs arrays on different conductive substrates through the in situ transformation of presynthesized layered double hydroxides (LDHs) NSs arrays, which provide an appropriate dissolution rate of metal ions in a mixed solvent. This strategy with LDHs as precursor is adaptable to bimetal-MOFs with different organic ligands and metal ions (such as NiCo-BDC (BDC = 1,4-dicarboxybenzene), NiCo-NDC (NDC = naphthalene-2,6-dicarboxylic acid), NiCo-TDA (TDA = 2,5-thiophenedicarboxylic acid), ZnCo-BDC BMNSs) on various substrates (such as nickel foam (NF), CC, and CFP, benefiting from the multimetal tunability and flexibility of LDHs. In addition, trimetal-MOF NSs Structure engineering of ultrathin metal-organic framework (MOF) nanosheets to self-supporting and well-aligned MOF superstructures is highly desired for diverse applications, especially important for electrocatalysis. In this work, a facile layered double hydroxides in situ transformation strategy is developed to synthesize ultrathin bimetal-MOF nanosheets (BMNSs) arrays on conductive substrates. This approach is versatile, and applicable to obtain various BMNSs or even trimetal-MOF nanosheets arrays on different substrates. As a proof of concept application, the obtained ultrathin NiCo-BDC BMNSs array exhibits an excellent...

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.

Developing an efficient catalyst for the electrocatalytic CO 2 reduction reaction (CO 2 RR) is highly desired because of environmental and energy issues. Herein, we report a single-atomic-site Cu catalyst supported by a Lewis acid for electrocatalytic CO 2 reduction to CH 4 . Theoretical calculations suggested that Lewis acid sites in metal oxides (e.g., Al 2 O 3 , Cr 2 O 3 ) can regulate the electronic structure of Cu atoms by optimizing intermediate absorption to promote CO 2 methanation. Based on these theoretical results, ultrathin porous Al 2 O 3 with enriched Lewis acid sites was explored as an anchor for Cu single atoms; this modification achieved a faradaic efficiency (FE) of 62% at −1.2 V (vs RHE) with a corresponding current density of 153.0 mA cm −2 for CH 4 formation. This work demonstrates an effective strategy for tailoring the electronic structure of Cu single atoms for the highly efficient reduction of CO 2 into CH 4 . KEYWORDS: CO 2 RR, Lewis acid, Al 2 O 3 , single-atom Cu catalyst, CH 4