Photocatalytic reduction of CO2 to value‐added fuel has been considered to be a promising strategy to reduce global warming and shortage of energy. Rational design and synthesis of catalysts to maximumly expose the active sites is the key to activate CO2 molecules and determine the reaction selectivity. Herein, we synthesize a well‐defined copper‐based boron imidazolate cage (BIF‐29) with six exposed mononuclear copper centers for the photocatalytic reduction of CO2. Theoretical calculations show a single Cu site including weak coordinated water delivers a new state in the conduction band near the Fermi level and stabilizes the *COOH intermediate. Steady‐state and time‐resolved fluorescence spectra show these Cu sites promote the separation of electron–hole pairs and electron transfer. As a result, the cage achieves solar‐driven reduction of CO2 to CO with an evolution rate of 3334 μmol g−1 h−1 and a high selectivity of 82.6 %.

Fundamental understanding of the dependence between the structure and composition on the electrochemical CO 2 reduction reaction (CO 2 RR) would guide the rational design of highly efficient and selective electrocatalysts.Amajor impediment to the deep reduction CO 2 to multi-carbon products is the complexity of carbon-carbon bond coupling. The chemically well-defined catalysts with atomically dispersed dual-metal sites are required for these CÀCc oupling involved processes.H ere,w ed eveloped ac atalyst (BIF-102NSs) that features Cl À bridged dimer copper (Cu 2 )u nits, which delivers high catalytic activity and selectivity for C 2 H 4 . Mechanistic investigation verifies that neighboring Cu monomers not only perform as regulator for varying the reaction barrier,b ut also affordd istinct reaction paths compared with isolated monomers,r esulting in greatly improved electroreduction performance for CO 2 .

The development of efficient and low-cost bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desirable for electrochemical energy conversion. Herein, this study puts forward a new Co decorated N,B-codoped interconnected graphitic carbon and carbon nanotube materials (Co/NBC) synthesized by direct carbonization of a cobalt-based boron imidazolate framework. It is demonstrated that the carbonization temperature can tune the surface structure and component of the resultant materials and optimize the electrochemically active surface area to expose more accessible active sites, effectively boosting the electrocatalytic activity. As a result, the optimized Co/NBC shows superior bifunctional catalytic activity and stability toward OER and HER in 1.0 m KOH solution. Furthermore, the catalyst can serve as both the anode and cathode for water splitting to achieve a current density of 10 mA cm −2 at a cell voltage of 1.68 V. Experimental results and theoretical calculations indicate that the excellent activity of Co/NBC catalyst benefits from the synergistic effect of partial oxidation of metallic cobalt, conductive N,B-codoped graphitic carbon and carbon nanotube, and the coupled interactions among these components. This work opens a promising avenue toward the exploration of boron imidazolate frameworks as efficient heteroatom-doped catalysts for electrocatalysis.

A porous crystalline boron imidazolate framework, with a high density of trinuclear cobalt clusters, exhibits efficient photocatalytic performance for CO2 reduction with a CO evolution rate of 5830 μmol g−1 h−1 under visible-light irradiation.

Photocatalytic reduction of CO 2 to value-added fuel has been considered to be apromising strategy to reduce global warming and shortage of energy.Rational design and synthesis of catalysts to maximumly expose the active sites is the key to activate CO 2 molecules and determine the reaction selectivity. Herein, we synthesizeawell-defined copper-based boron imidazolate cage (BIF-29) with six exposed mononuclear copper centers for the photocatalytic reduction of CO 2 . Theoretical calculations show as ingle Cu site including weak coordinated water delivers anew state in the conduction band near the Fermi level and stabilizes the *COOH intermediate. Steady-state and time-resolved fluorescence spectra showthese Cu sites promote the separation of electron-hole pairs and electron transfer.A saresult, the cage achieves solar-driven reduction of CO 2 to CO with an evolution rate of 3334 mmol g À1 h À1 and ahigh selectivity of 82.6 %.With the development of human activities,t he excessive emission of carbon dioxide (CO 2 )r esults in an increasingly serious environmental problem. To address this issue,o ne of the most promising solutions is direct photochemical reduction of CO 2 to useful chemicals or fuels such as methane, methanol, carbon monoxide,and formic acid. [1] Among these possible target products,the two-electron reduction of CO 2 to CO is al ess hindered process and plays an important role in the chemical industry. [1a,2] To date,m uch research has been devoted to developing selective catalysts for reduction of CO 2 to CO. [3] Precious metals have been identified as promising candidates for CO 2 reduction to CO but their practical applications are still limited. Copper as an earth-abundant metal is ac ritical metal in photosynthesis [4] and Cu-based materials have been regarded as promising catalysts for efficiently photo-or electro-catalyzing CO 2 reduction. [5] To date,v arious Cu-based catalysts have been developed but limited product selectivity due to the presence of multiple neighboring sites for involving CO 2 reduction. To enhance product selectivity,aconventional approach is to tailor the number of nearest neighboring accessible Cu atoms,s uch as reducing the particle size [6] or hybridizing Cu with other metals. [7] Besides these,i ntroducing single active site in ac atalyst has been proven to be an effective strategy to study the reactive pathway and enhance the activity for CO 2 reduction reaction (CO2RR). [8] In particular,t he presence of unsaturated coordinated single active sites or defect can modify the electron structure of catalysts,w hich could stabilize the reaction intermediates and thus depress the energy barrier of the photoreduction CO 2 . [9] Recent studies demonstrate that this type of catalyst exhibits high activity for reducing CO 2 to CO. [10] However, such ac atalyst is generally obtained through pyrolysis of Ni, or Co-based metal-organic frameworks (MOFs) or coordination polymers. [10,11] In contrast, no Cu-based catalysts with single active sites have been developed for the pho...

Separation of ethylene (C2H4) from ethane (C2H6) through one step is desirable but challenging in view of their similar sizes and physical properties. Introduction of pore partition agents into metal–organic frameworks (MOFs) endows materials with multivariate porous environments for gas adsorption and separation. Here, we report a novel microporous boron imidazolate framework (BIF-108-Zn) that integrates both organic ligands and extra-framework species as pore partition agents to divide the interconnected channels into isolated cages. This structure possesses a high pore volume with a reduced pore size and a functionalized pore surface to realize preferential binding of C2H6 over C2H4. Dynamic breakthrough measurements demonstrated that BIF-108-Zn can directly produce polymer-grade C2H4 with a productivity of 0.69 mmol/g at 298 K and 1 bar from a binary mixture of C2H6/C2H4. Furthermore, the relatively low isosteric enthalpy value endows it with good regenerability and high stability, as verified by multiple adsorption separation tests.

Improving the stability and charge transportation efficiency of lead halide perovskites is the key for their practical photocatalytic applications. Herein, we designed and synthesized a microporous boron imidazolate framework (BIF-122-Co) by cross-linking boron imidazolate ligands and benzene carboxylate with metal ions, which was further used as a host matrix to encapsulate CsPbBr3 perovskite via a sequential deposition route to obtain a composite material, CsPbBr3/BIF-122-Co. Due to the intimate host–guest interfacial contact in the composite material, BIF-122-Co not only provided a physical protective barrier for CsPbBr3 but also accelerated the photoinduced charge separation process in the photocatalytic CO2 reduction reaction. The work provided a guide for exploration of excellent perovskite/metal–organic framework (MOF) composites.

Titanium-based coordination cages are fascinating in the field of supramolecular and photophysical chemistry. Herein, we address the unprecedented supramolecular co-assembly arrangement of a cubic Ti8L12 cage with [Ti­(DMF)6] species and Ti12-oxo cluster, contributing to the cocrystals of {Ti8L12 + Ti­(DMF)6} (PTC-116) and {Ti8L12 + Ti12-oxo} (PTC-117). The ESI-MS and 1H NMR measurements reveal their stability in solution. The photophysical properties of these supramolecular complexes in solution, including light absorption and photoluminescent behaviors, were further investigated.