Bioinspired porous three-coordinated single-atom Fe nanozyme with oxidase-like activity for tumor visual identification via glutathione.

Inspired by structures of natural metalloenzymes, a biomimetic synthetic strategy is developed for scalable synthesis of porous Fe-N single atom nanozymes (pFeSAN) using hemoglobin as Fe-source and template. pFeSAN delivers 3.3- and 8791-fold higher oxidase-like activity than Fe-N and FeO nanozymes.

Regulation of frustrated Lewis pairs on CeO facilitates tandem transformation of styrene and CO.

The frustrated Lewis pair (FLP) site of (Ce, Ce)-O on the CeO(110) surface undergoes reconstruction to form (La, Ce)-O upon La-doping. The FLP site of (La, Ce)-O with the tailored local Lewis acid-base property and increased spatial distance between the Lewis acid and base facilitates the tandem transformation of styrene and CO through the weakened adsorption of CO while maintaining activation.

Grand Canonical Ensemble Modeling of Electrochemical Interfaces Made Simple.

Grand canonical ensemble (GCE) modeling of electrochemical interfaces, in which the electrochemical potential is converged to a preset constant, is essential for understanding electrochemistry and electrocatalysis at the electrodes. However, it requires developing efficient and robust algorithms to perform practical and effective GCE modeling with density functional theory (DFT) calculations. Herein, we developed an efficient and robust fully converged constant-potential (FCP) algorithm based on Newton's method and a polynomial fitting to calculate the necessary derivative for DFT calculations.

Single-atom catalysis enabled by high-energy metastable structures.

Owing to limited degrees of freedom, the active sites of stable single-atom catalyst (SAC) often have one structure that is energetically much lower than other local-minimum structures. Thus, the SAC adopts one lowest-energy structure (LES) with an overwhelmingly larger proportion than any other high-energy metastable structure (HEMS), and the LES is commonly assumed to be solely responsible for the catalytic performance of an SAC. Herein, we demonstrate with SACs anchored on CeO that the HEMS of an SAC, even though its proportion remains several orders of magnitude lower than the LES throughout the catalytic reaction, can dictate catalysis with extraordinary activity arising from its unique coordination environment and oxidation state.

Recent progress of theoretical studies on electro- and photo-chemical conversion of CO with single-atom catalysts.

The CO reduction reaction (CORR) into chemical products is a promising and efficient way to combat the global warming issue and greenhouse effect. The viability of the CORR critically rests with finding highly active and selective catalysts that can accomplish the desired chemical transformation. Single-atom catalysts (SACs) are ideal in fulfilling this goal due to the well-defined active sites and support-tunable electronic structure, and exhibit enhanced activity and high selectivity for the CORR.

Ce-hydroxamate metal-organic frameworks for photocatalytic H generation.

Exploring the rich coordination chemistry of Ce, here we report two new entries in the emerging category of hydroxamate-based metal-organic frameworks (MOFs). The two Ce-hydroxamate MOFs exhibited different band structures and photoelectrochemical properties based on their respective coordinative environments and overall structures, leading to varied H generation performances.

Surface Water as an Initial Proton Source for the Electrochemical CO Reduction Reaction on Copper Surfaces.

We have employed in situ electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) and density functional theory (DFT) calculations to study the CO reduction reaction (CORR) on Cu single-crystal surfaces under various conditions. Coadsorbed and structure-/potential-dependent surface species, including *CO, Cu-O , and Cu-OH , were identified using electrochemical spectroscopy and isotope labeling. The relative abundance of *OH follows a "volcano" trend with applied potentials in aqueous solutions, which is yet absent in absolute alcoholic solutions.

Insights into the Interfacial Lewis Acid-Base Pairs in CeO -Loaded CoS Electrocatalysts for Alkaline Hydrogen Evolution.

Despite the known efficacy of CeO as a promoter in alkaline hydrogen evolution reaction (HER), the underlying mechanism of this effect remains unclear. CoS , a pyrite-type alkaline HER electrocatalyst, suffers from sluggish HER kinetics and severe catalyst leaching due to its weak water dissociation kinetics and oxygen-related corrosion. Herein, it is demonstrated that the interfacial Lewis acid-base Ce∙∙∙S pairs in CeO -loaded CoS effectively improve the catalytic activity and durability.

Spatial intimacy of binary active-sites for selective sequential hydrogenation-condensation of nitriles into secondary imines.

Precisely controlling the spatial intimacy of multiple active sites at sub-nanoscale in heterogeneous catalysts can improve their selectivity and activity. Herein, we realize a highly selective nitrile-to-secondary imine transformation through a cascaded hydrogenation and condensation process by Pt/CoBO comprising the binary active sites of the single-dispersed Pt and interfacial Lewis acidic B. Atomic Pt sites with large inter-distances (>nanometers) only activate hydrogen for nitrile hydrogenation, but inhibit condensation.

Interfacial Frustrated Lewis Pairs of CeO Activate CO for Selective Tandem Transformation of Olefins and CO into Cyclic Carbonates.

Effective activation of CO is a prerequisite for efficient utilization of CO in organic synthesis. Precisely controlling the interfacial events of solids shows potential for activation. Herein, defect-enriched CeO with constructed interfacial frustrated Lewis pairs (FLPs, two adjacent Ce···O) effectively activates CO via the interactions between C/Lewis basic lattice O and the two O atoms in CO/two adjacent Lewis acidic Ce ions.

Towards highly active Pd/CeO for alkene hydrogenation by tuning Pd dispersion and surface properties of the catalysts.

Extensive applications of noble metals as heterogeneous catalysts are limited by their global reserve scarcity and exorbitant price. Identifying the intrinsic active nature of a catalyst benefits the designing of catalysts with trace amounts of noble metals; these catalysts display better or comparable overall catalytic efficiency than their heavily loaded counterparts. Herein, systematic studies on Pd dispersion and surface properties of a series of Pd/CeO catalysts for styrene hydrogenation showed that high Pd dispersion and surface abundant defects of the catalysts are essential to realize superior activity.

Highly Efficient and Robust Nickel Phosphides as Bifunctional Electrocatalysts for Overall Water-Splitting.

To search for the efficient non-noble metal based and/or earth-abundant electrocatalysts for overall water-splitting is critical to promote the clean-energy technologies for hydrogen economy. Herein, we report nickel phosphide (NixPy) catalysts with the controllable phases as the efficient bifunctional catalysts for water electrolysis. The phases of NixPy were determined by the temperatures of the solid-phase reaction between the ultrathin Ni(OH)2 plates and NaH2PO2·H2O.

Hollow Fluffy Co3O4 Cages as Efficient Electroactive Materials for Supercapacitors and Oxygen Evolution Reaction.

Nano-/micrometer multiscale hierarchical structures not only provide large surface areas for surface redox reactions but also ensure efficient charge conductivity, which is of benefit for utilization in areas of electrochemical energy conversion and storage. Herein, hollow fluffy cages (HFC) of Co3O4, constructed of ultrathin nanosheets, were synthesized by the formation of Co(OH)2 hollow cages and subsequent calcination at 250 °C. The large surface area (245.

Three sulphated polysaccharides isolated from the mucilage of mud snail, Bullacta exarata philippi: characterization and antitumour activity.

Three sulphated polysaccharides, coded as BEMPA, BEMPB(1), BEMPB(2), were extracted from the mucilage of mud snail of Bullacta exarata and purified by DEAE-cellulose ion-exchange and size-exclusion chromatography. Structural analysis of purified polysaccharides by chemical and biochemical methods revealed BEMPA was a high (1→3,4)-linked mannose-containing polysaccharide with molecular weight of 22,977 Da. BEMPB(1), with molecular weight of 64,117 Da, was a high (1→3)-linked arabinose-containing polysaccharide.