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To improve the electrocatalytic conversion of carbon dioxide (CO2) into C2+ products (such as ethylene (C2H4) and ethanol (CH3CH2OH), etc.) is of great importance, but remains challenging. Herein, we proposed a strategy that directs the C-C coupling pathway through enriching and confining the carbon monoxide (CO) intermediate to internal pores of Cu nanocubes, for electrocatalytic reduction of CO2 into C2+ chemicals. In H-type cell, the Faraday efficiency (FE) for ethylene and ethanol reaches 70.3% at −1.28 V versus the reversible hydrogen electrode (vs. RHE), with a current density of 47.9 mA·cm−2. In flow cell, the total current density is up to 340.3 mA·cm−2 at −2.38 V (vs. RHE) and the FE for C2+ products is 67.4%. Experimental and theoretical studies reveal that both the CO intermediate adsorption and C-C coupling reaction on such an internal porous catalyst are facilitated, thus improving CO2-to-C2+ conversion efficiency. [ABSTRACT FROM AUTHOR]

To develop high-performance metal-organic frameworks (MOFs) for catalysis is of great importance. Here, we synthesized the mesoporous Cu3−xZnx(BTC)2 (BTC = benzene-1,3,5-tricarboxylate) nanocubes in a deep eutectic solvent of ZnCl2/ethylene glycol solution. The route can proceed at room temperature and the reaction time needed is shortened to be 30 min, which is superior to the conventional solvothermal route that usually needs high temperature and long reaction time. The formation mechanism of the mesoporous Cu3−xZnx(BTC)2 nanocubes in deep eutectic solvent (DES) was investigated by in situ synchrotron X-ray diffraction/small angle X-ray scattering/X-ray absorption fine structure conjunction technique. The mesoporous Cu3−xZnx(BTC)2 nanocubes exhibit high catalytic activity and reusability for cyanosilylation reaction of benzaldehyde and aerobic oxidation reaction of benzylic alcohol. [ABSTRACT FROM AUTHOR]

Mn-based catalysts have exhibited promising performance in low-temperature selective catalytic reduction of NOx with NH3 (NH3-SCR). However, challenges such as H2O- or SO2-induced poisoning to these catalysts still remain. Herein, we report an efficient strategy to prepare the dual single-atom Ce-Ti/MnO2 catalyst via ball-milling and calcination processes to address these issues. Ce-Ti/MnO2 showed better catalytic performance with a higher NO conversion and enhanced H2O- and SO2-resistance at a low-temperature window (100–150 °C) than the MnO2, single-atom Ce/MnO2, and Ti/MnO2 catalysts. The in situ infrared Fourier transform spectroscopy analysis confirmed there is no competitive adsorption between NOx and H2O over the Ce-Ti/MnO2 catalyst. The calculation results showed that the synergistic interaction of the neighboring Ce-Ti dual atoms as sacrificial sites weakens the ability of the active Mn sites for binding SO2 and H2O but enhances their binding to NH3. The insight obtained in this work deepens the understanding of catalysis for NH3-SCR. The synthesis strategy developed in this work is easily scaled up to commercialization and applicable to preparing other MnO2-based single-atom catalysts. [ABSTRACT FROM AUTHOR]

To produce metal-organic framework (MOF) catalysts with both high activity and durability is interesting but challenging. We report an amorphous MOF (NH2-MIL-68), which combines the advantages of (1) a large number of open metal sites, (2) the basic building blocks and connectivity of crystalline NH2-MIL-68, and (3) hierarchically meso- and microporous structure. It exhibits high performances in electrocatalytic reduction of CO2 and photochemical cycloaddition of CO2 under mild conditions. For the former reaction, the maximum Faradaic efficiency for product formic acid (FEHCOOH) reaches 93.3% with a current density of 34.2 mA·cm−2 at −2.05 V vs. Ag/Ag+ catalyzed by amorphous NH2-MIL-68, while the crystalline NH2-MIL-68 shows FEHCOOH of 67.7% with considerable productions of CO and H2 at the same experimental conditions. For the photochemical cycloaddition of CO2 with styrene oxide, the yield by amorphous NH2-MIL-68 can reach 94.1% at 12 h, which is higher than the reported value under similar conditions. The structure—efficiency relationship of the catalyst for the two reactions was investigated. This work opens up new possibility for designing high-performance MOF and MOF-based catalysts. [ABSTRACT FROM AUTHOR]

It is of great importance to develop facile strategies to synthesize catalysts with desirable compositions and structures for high-performance photocatalytic hydrogen generation. In this work, we put forward an ionic liquid assisted one-pot route for the synthesis of heteroatom-doped Pt/TiO2 composite material. This route is simple, environmentally benign and adjustable owing to the designable properties of ionic liquids. The as-synthesized Pt/TiO2 nanocrystals exhibit high activity and stability for the photocatalytic hydrogen generation under simulated solar irradiation. This method can be easily applied to the synthesis of various kinds of metal/TiO2 composites doped with desirable heteroatoms (e.g., F, Cl, Br, etc). [ABSTRACT FROM AUTHOR]