Yu Lin

Biocatalytic intermolecular [2+1] cyclopropanation of olefins exhibits the advantages of green, mild, high activity, and high selectivity. Its reaction mechanism holds significant inspiration for sustainable chemical synthesis. However, the challenges of structural stability, recyclability, and narrow substrate specificity restrict its synthetic application. Biomimetic catalytic systems integrate the strengths of organic chemistry, biochemistry, and materials science. By simulating the green synthesis mechanisms of natural enzymes and optimizing artificial structures, inherent issues of enzymes can be overcome. This review focuses on the catalytic mechanisms of cyclopropane enzymes, particularly their green catalytic advantages. It summarizes the rational design and synthesis strategies of artificial biomimetic catalysts and highlights the breakthroughs in catalytic effects. Finally, the article also outlines the design principles and future prospects for natural cyclopropane enzymes and biomimetic catalysts, aiming to drive the field of alkene cyclopropanation toward more green and efficient levels.

Serine hydrolases, as a class of green catalysts with hydrolytic and dehydrating activities, hold significant application value in the fields of biosynthesis and organic synthesis. However, practical applications face numerous challenges, including maintaining enzyme stability and managing usage costs. PepNzymes-SH, an emerging green catalytic material with enzyme-like activity, overcomes the operational limitations of natural enzymes and holds great promise as a substitute for hydrolases. Unfortunately, a systematic review of the design strategies for PepNzymes-SH is currently lacking. The core significance of this report lies in providing researchers with a comprehensive understanding and theoretical guidance through the summarization and performance evaluation of different design strategies of PepNzymes-SH. This review summarizes strategies for simulating and enhancing the stability of serine hydrolase active sites, oxyanion holes, and hydrophobic environmental structures. By comparing their catalytic activities, we assess the performance changes brought about by different strategies. Furthermore, the applications of PepNzymes-SH in the chemical, biomedicine, and environmental fields are also discussed.

Developing noble-metal-free, high-efficiency, and durable electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) is a challenging problem in electrochemical water electrolysis. In this work, a facile continuous two-step hydrothermal method followed by electrodeposition to fabricate NiFe-LDH integrated with CoFe₂O₄@Co₃S₄ nanoflowers supported by carbon fiber paper (NiFe-CoFe₂O₄@Co₃S₄/CFP) as a full water-splitting electrocatalyst was developed. Serving as an anode catalyst, the fabricated heterostructure electrode shows extraordinary OER performance with an overpotential of 233.3 and 244.0 mV to achieve a current density of 50 and 100 mA cm⁻², respectively. Serving as a cathode catalyst, NiFe-CoFe₂O₄@Co₃S₄/CFP exhibits superior electrocatalytic activities with an overpotential of 98 mV to achieve current densities of 10 mA cm⁻². Furthermore, when serving as both the anode and cathode catalyst in an electrolyzer for overall water splitting, the as-prepared electrode only requires a cell potential as low as 1.53 V to reach a current density of 10 mA cm⁻² and excellent durability for more than 48 h in alkaline media.