Highly Stable 72-Nuclearity Nanocages for Efficient Synthesis of Aryl Nitriles via Ni/Cu Synergistic Catalysis.

Seeking noble-metal-free catalysts for efficient synthesis of aryl nitriles under mild conditions poses a significant challenge due to the use of hypertoxic cyanides or high-pressure/temperature NH3/O2 in conventional synthesis processes. Herein, we developed a novel framework 1 assembled by [Ni72] nanocages with excellent solvents/pH stability. To investigate the structure-activity relationship of catalytic performance, several isostructural MOFs with different molar ratios of Ni/Cu by doping Cu2+ into framework 1 (Ni0.59Cu0.41 (2), Ni0.81Cu0.19 (3), Ni0.88Cu0.12 (4), and Ni0.92Cu0.08 (5)) were prepared. Catalytic studies revealed that catalyst 3 exhibited remarkable performance in the synthesis of aryl nitriles, utilizing a formamide alternative to hypertoxic NaCN/KCN. Notably, catalyst 3 achieved an excellent TOF value of 9.8 h-1. Furthermore, catalyst 3 demonstrated its applicability in a gram-scale experiment and maintained its catalytic performance even after six recycling cycles, owing to its high stability resulting from significant electrostatic and orbital interactions between the Ni center and ligands as well as a large SOMO-LUMO energy gap supported by DFT calculations. Control experiments and DFT calculations further revealed that the excellent catalytic performance of catalyst 3 originated from the synergistic effect of Ni/Cu. Importantly, this work not only provides a highly feasible method to construct highly stable MOFs containing multinuclear nanocages with exceptional catalytic performance but also represents the first example of a heterogeneous catalyst for the synthesis of aryl nitriles using formamide as the cyanide source.

A Facile Strategy to Obtain Low-Cost and High-Performance Gold-Based Catalysts from Artificial Electronic Waste by [Zr48 Ni6 ] Nano-Cages in MOFs for CO2 Electroreduction to CO.

Expensive gold-based catalysts are frequently used for electrochemical CO2 reduction into CO. A feasible approach to obtain low-cost Au-based catalysts is needed. Herein, a novel framework 1 assembled from [Zr48 Ni6 ] nano-cages is prepared. It exhibits a high BET surface area of 1569 m2 g-1 and high solvents/pH stability. 1 can not only selectively extract AuCl4 - from artificial electronic waste, but can then be transformed into low-cost catalyst Au nanoparticle@1-x (Au NPs@1-x, x=1, 2, 3, 4) with tuneable Au NPs sizes. The CO2 RR investigations revealed that the Au NPs@1-3 displayed an excellent FECO of 95.2 % with a current density of 102.9 mA cm-2 at -1.1 V, and such high catalytic activity can be maintained for at least 15 h without obvious decrease because the confinement effect of [Zr48 Ni6 ] nano-cages prevents Au NPs agglomeration. This work offers a facile strategy to obtain low-cost and high-performance Au-based catalysts for various reactions activated by Au.

A Facile Strategy for Constructing a Carbon-Particle-Modified Metal-Organic Framework for Enhancing the Efficiency of CO2 Electroreduction into Formate.

Electrocatalytic reduction of CO2 by metal-organic frameworks (MOFs) has been widely investigated, but insufficient conductivity limits application. Herein, a porous 3D In-MOF {(Me2 NH2 )[In(BCP)]⋅2 DMF}n (V11) with good stability was constructed with two types of channels (1.6 and 1.2 nm diameter). V11 exhibits moderate catalytic activity in CO2 electroreduction with 76.0 % of Faradaic efficiency for formate (FEHCOO- ). Methylene blue molecules of suitable size and pyrolysis temperature were introduced and transformed into carbon particles (CPs) after calcination. The performance of the obtained CPs@V11 is significantly improved both in FEHCOO- (from 76.0 % to 90.1 %) and current density (2.2 times). Control experiments show that introduced CPs serve as accelerant to promote the charges and mass transfer in framework, and benefit to sufficiently expose active sites. This strategy can also work on other In-MOFs, demonstrating the universality of this method for electroreduction of CO2 .