Qian He

Porous carbon materials are considered promising anodes for lithium-ion batteries (LIBs) due to their high theoretical capacities and rich natural resources. However, the poor cycle performance and sluggish lithium diffusion kinetics limit their application. Here, single atom metal (M = Fe, Co, Ni, and Mn) and N co-doped porous carbons (M-N-C) were successfully prepared by a polymer-pyrolysis method. single atom metal and N co-doping provided a larger number of anchoring sites for Li⁺ adsorption, enlarged the inter-distance of graphenes, and endowed overall atomic structural stability to the materials by constructing a coordination mode of M-N-C; the materials showed excellent cycle performance and rate performance, and after 1000 cycles, the discharge capacity was still 635 mA h g^-1 at 0.5 A g^-1. The galvanostatic charge/discharge curves and cyclic voltammetry of M-N-C revealed that bulk capacity arises from a capacitive-controlled process involving Li-ion adsorption/desorption on active site surfaces. In addition, Mn-N-C had excellent electrode kinetics, which showed smaller charge transfer resistance (21.4 Ω). This work provides inspiration for the design of superior porous carbons with a stable structure for lithium-ion batteries and energy storage.

Selective hydrogenation of cinnamaldehyde (CAL) is an important model reaction for evaluating the activity and selectivity of heterogeneous catalysts. Herein, a Pd–Ni bimetallic single-atom catalyst (Pd₁–Ni₁/Al₂O₃) was fabricated through a...

A nanozyme with neighboring single‐iron sites (Fe₂‐SAzyme) was introduced as a bioinspired catalase mimic, featuring excellent activity under varied conditions, twice as high as that of random Fe₁‐SAzyme and ultrahigh H₂O₂ affinity as that of bioenzymes. Surprisingly, the interatomic spacing tuning between adjacent iron sites also suppressed the competitive peroxidase pathway, remarkably increasing the catalase/peroxidase selectivity up to ~6 times compared to Fe₁‐SAzyme. This dramatically switched the catalytic activity of Fe‐SAzymes from generating (i.e. Fe₁‐SAzymes, preferably mimicking peroxidase) to scavenging ROS (i.e. Fe₂‐SAzymes, dominantly mimicking catalase). Theoretical and experimental investigations suggested that the pairwise single‐iron sites may serve as a robust molecular tweezer to efficiently trap and decompose H₂O₂ into O₂, via cooperative hydrogen‐bonding induced end‐bridge adsorption. The versatile mechano‐assisted in situ MOF capsulation strategy enabled facile access to neighboring M₂‐SAzyme (M=Fe, Ir, Pt), even up to a 1000 grams scale, but with no obvious scale‐up effect for both structures and performances.

A nanozyme with neighboring single‐iron sites (Fe₂‐SAzyme) was introduced as a bioinspired catalase mimic, featuring excellent activity under varied conditions, twice as high as that of random Fe₁‐SAzyme and ultrahigh H₂O₂ affinity as that of bioenzymes. Surprisingly, the interatomic spacing tuning between adjacent iron sites also suppressed the competitive peroxidase pathway, remarkably increasing the catalase/peroxidase selectivity up to ~6 times compared to Fe₁‐SAzyme. This dramatically switched the catalytic activity of Fe‐SAzymes from generating (i.e. Fe₁‐SAzymes, preferably mimicking peroxidase) to scavenging ROS (i.e. Fe₂‐SAzymes, dominantly mimicking catalase). Theoretical and experimental investigations suggested that the pairwise single‐iron sites may serve as a robust molecular tweezer to efficiently trap and decompose H₂O₂ into O₂, via cooperative hydrogen‐bonding induced end‐bridge adsorption. The versatile mechano‐assisted in situ MOF capsulation strategy enabled facile access to neighboring M₂‐SAzyme (M=Fe, Ir, Pt), even up to a 1000 grams scale, but with no obvious scale‐up effect for both structures and performances.

A biomimetic catalytic approach for the aerobic oxidation of C–sp(3)–H bonds using galactose oxidase model compound was developed. EPR showed that the Cu^I-radical intermediate species was critical for O₂ activation.

More electron depletion of the Pt center of the Pt ₁ /Co ₃ O ₄ -c surface facilitates overall electron transfer from the B atom to the ammonia borane (AB) molecule, which ensures the highest activity among Pt ₁ /Co ₃ O ₄ -x in the hydrolytic dehydrogenation of AB reaction.