Tailoring N-Coordination Environment by Ligand Competitive Thermolysis Strategy for Efficient Oxygen Reduction

Matching Bidentate Ligand Anchoring: an Accurate Control Strategy for Stable Single-Atom/ZIF Nanocatalysts

Improving metal loading and controlling the coordination environment is nontrivial and challenging for single-atom catalysts (SACs), which have the greatest atomic efficiency and largest number of interface sites. In this study, a matching bidentate ligand (MBL) anchoring strategy is designed for the construction of CuN₄ SACs with tunable coordination environments (Cu loading range from 0.4 to15.4 wt.%). The obtained Cu SA/ZIF and Cu SA/ZIF* (0.4 wt.%) (ZIF and ZIF* = Zeolitic imidazolate framework with Matching bidentate N-ligands) nanocomposites exhibit superior performance in homo-coupling of phenyl acetylene under light irradiation (TON = 580, selectivity > 99%), which is 22 times higher than that of Cu SA/NC-800 (NC = N-doped porous carbon). Experiments and density functional theory calculations confirmed that the specific Cu five-membered ring formed using the MBL anchoring strategy is the key to the immobilization of isolated Cu atoms. This strategy provides a basis for the construction of M SA/MOF, which has the potential to narrow the gap between experimental and theoretical catalysis, as further confirmed by the successful preparation of Fe SA/ZIF and Ni SA/ZIF.

Micro/macrostructure and multicomponent design of catalysts by MOF-derived strategy: Opportunities for the application of nanomaterials-based advanced oxidation processes in wastewater treatment

Advanced oxidation processes (AOPs) have demonstrated an effective wastewater treatment method. But the application of AOPs using nanomaterials as catalysts is challenged with a series of problems, including limited mass transfer, surface fouling, poor stability, and difficult recycling. Recently, metal-organic frameworks (MOFs) with high tunability and ultrahigh porosity are emerging as excellent precursors for the delicate design of the structure/composition of catalysts and many MOF-derived catalysts with distinct physicochemical characteristics have shown optimized performance in various AOPs. Herein, to elucidate the structure-composition-performance relationship, a review on the performance optimization of MOF-derived catalysts to overcome the existing problems in AOPs by micro/macrostructure and multicomponent design is given. Impressively, MOF-derived strategy for the design of catalyst materials from the aspects of microstructure, macrostructure, and multicomponent (polymetallic, heteroatom doping, M/C hybrids, etc.) is firstly presented. Moreover, important advances of MOF-derived catalysts in the application of various AOPs (Fenton, persulfate-based AOPs, photocatalysis, electrochemical processes, hybrid AOPs) are summarized. The relationship between the unique micro/macrostructure and/or multicomponent features and performance optimization in mass transfer, catalytic efficiency, stability, and recyclability is clarified. Furthermore, the challenges and future work directions for the practical application of MOF-derived catalysts in AOPs for wastewater treatment are provided.

Deep-Breathing Fe-Doped Superstructure Modified by Polyethyleneimine as Oxygen Reduction Electrocatalysts for Zn-Air Batteries

The development of economical, robust and high active non-precious metal oxygen reduction reaction (ORR) electrocatalysts to replace the precious metal is extremely crucial for the widespread applications of metal-air batteries....