Electrochemical reduction of CO 2 to chemicals and fuels is an interesting and attractive way to mitigate greenhouse gas emissions and energy shortages. In this work, we report the use of atomic In catalysts for CO 2 electroreduction to CO. The atomic In catalysts were anchored on N-doped carbon (In A /NC) through pyrolysis of In-based metal−organic frameworks (MOFs) and dicyandiamide. It was discovered that In A /NC had outstanding performance for selective CO production in the mixed electrolyte of ionic liquid/ MeCN. It is different from those common In-based materials, in which formate/ formic acid is formed as the main product. The faradaic efficiency (FE) of CO and total current density were 97.2% and 39.4 mA cm -2 , respectively, with a turnover frequency (TOF) of ∼40 000 h −1 . It is one of the highest TOF for CO production to date for all of the catalysts reported. In addition, the catalyst had remarkable stability. Detailed study indicated that In A /NC had higher double-layer capacitance, larger CO 2 adsorption capacity, and lower interfacial charge transfer resistance, leading to high activity for CO 2 reduction. Control experiments and theoretical calculations showed that the In−N site of In A /NC is not only beneficial for dissociation of COOH* to form CO but also hinders formate formation, leading to high selectivity toward CO instead of formate.

Metal‐organic frameworks (MOFs) are of quite a significance in the field of inorganic‐organic hybrid crystals. Especially, MOFs have attracted increasing attention in recent years due to their large specific surface area, desirable electrical conductivity, controllable porosity, tunable geometric structure, and excellent thermal/chemical stability. Some recent studies have shown that carbon materials prepared by MOFs as precursors can retain the privileged structure of MOFs, such as large specific surface area and porous structure and, in contrast, realize in situ doping with heteroatoms (eg, N, S, P, and B). Moreover, by selecting appropriate MOF precursors, the composition and morphology of the carbon products can be easily adjusted. These remarkable structural advantages enable the great potential of MOF‐derived carbon as high‐performance energy materials, which to date have been applied in the fields of energy storage and conversion systems. In this review, we summarize the latest advances in MOF‐derived carbon materials for energy storage applications. We first introduce the compositions, structures, and synthesis methods of MOF‐derived carbon materials, and then discuss their applications and potentials in energy storage systems, including rechargeable lithium/sodium‐ion batteries, lithium‐sulfur batteries, supercapacitors, and so forth, in detail. Finally, we put forward our own perspectives on the future development of MOF‐derived carbon materials.

With the development of portable electronic equipment, electric vehicle, space technology, and power‐grid and energy‐storage technology, new efficient energy‐storage devices need to be developed urgently. Recently, asymmetric supercapacitors (ASCs) have attracted ever‐increasing interest as one of the most promising energy‐storage devices given their remarkable advantages of wide operation voltage window, high power density, and moderate energy density. However, to meet the needs of the rapid development of electronic equipment, it is necessary to optimize the electrode materials and device design to further boost the energy density of ASCs. In recent years, numerous attempts have been made to improve the energy density of ASC devices by increasing the capacitance and/or enlarging the voltage window. Here, recent smart strategies are highlighted, including the introduction of intrinsic defects, element doping, and surface functionalization to increase the capacitance of the electrode materials, and optimizing the electrolyte and electrode materials, as well as their surface charge, to broaden the voltage of cells. Moreover, the current challenges and future opportunities for the development of high‐performance ASCs are also discussed.

A conjugated donor-acceptor porphyrin small molecule was designed and synthesized with diketopyrrolopyrrole as the acceptor unit. The new porphyrin-based small molecule exhibits broad and intense absorption in the visible and near IR regions, and the hole mobility and the power conversion efficiency of the bulk heterojunction devices based on the porphyrin : [6,6]-phenyl-C-61-butyric acid methyl ester (1 : 1, w/w) are increased up to 4.6 Â 10 À5 cm 2 V À1 s À1 and 3.71%, respectively, which are further enhanced to 1.6 Â 10 À4 cm 2 V À1 s À1 and 4.78%, respectively, upon the introduction of 3.0 vol% of pyridine additive. Further studies show that the performance of the solar cells based on other zinc porphyrins could also be improved by the pyridine additive.

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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.

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.

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