Significant Enhancement Catalytic Activity of Nitrile Hydratase by Balancing the Subunits Expression.

Escherichia coli (E. coli) is the most commonly used bacterial recombinant protein production system due to its easy genetic modification properties. In our previous study, a recombinant plasmid expressing the Fe-type nitrile hydratase derived from Rhodococcus erythropolis CCM2595 (ReNHase) was successfully constructed and the recombinant ReNHase exerted an excellent catalytic effect on dinitrile compounds.

In Situ Synthesis of High-Entropy (Oxy)Hydroxides Via Electrochemical Reconfiguration As Catalysts For Efficient Water Oxidation.

Surface reconstruction plays a pivotal role in enhancing the activity of the oxygen evolution reaction (OER), particularly in terms of the structural transformation from metal oxides to (oxy)hydroxides. Herein, a novel (oxy)hydroxide (FeCoNiCuMoOOH) with high entropy is developed by the electrochemical reconstitution of corresponding oxide (FeCoNiCuMoO). Significantly, the FeCoNiCuMoOOH exhibits much higher OER electrocatalytic activity and durability with an overpotential as low as 201 mV at a current density of 10 mA cm, and with a Tafel slope of 39.

Vanadium-catalyzed Hydration of 2-Cyanopyrazine to Pyrazinamide with Unique Substrate Specificity.

Pyrazinamide is an important medicine used for the treatment of tuberculosis(TB). The preparation of pyrazinamide via catalytic hydration of 2-cyanopyrazine is of great economic interest with high atomic economy. Heterogeneous non-precious transition metal-catalyzed hydration of nitriles under neutral reaction conditions would be rather attractive.

The correlation of molecule weight of chitosan oligomers with the corresponding viscosity and antibacterial activity.

In order to explore the correlation between the viscosity of chitosan oligomers-acetic solution and its viscosity average molecular weight (M), and determine the M range with a strong bactericidal effect. A series of chitosan oligomers were obtained by degraded chitosan (728.5 kDa) with dilute acid and chitosan oligomer (101.

PtFeCoNiCu High-Entropy Alloy Catalyst for Aqueous-Phase Hydrogenation of Maleic Anhydride.

High-entropy alloys (HEAs), as new heterogeneous catalytic materials, possess remarkable catalytic performance in numerous reactions. However, rational and controllable synthesis of these complex structures remains a challenge. In this work, bulk and carbon nanotube (CNT)-supported ultrasmall PtFeCoNiCu HEA nanoparticles with an average particle size of 1.

Structural Construction of Au-Pd Nanocomposite for Alkali-Free Oxidation of Benzyl Alcohol.

A bimetallic Au-Pd system is an alternative candidate to catalyze primary alcohol oxidation and is of crucial importance for the sustainable chemical industry. However, understanding the bimetallic system in terms of the nanostructure is still challenging. Herein, we adopt the in situ colloid immobilization to obtain a series of bimetallic AuPd/CNT samples supported by carbon nanotubes (CNTs).

A nanobiocatalytic system based on the self-assembly of ferrous phosphate with a high regioselectivity nitrile hydratase.

Our previous study identified a novel nitrile hydratase (NHase) with remarkable biotransformation activity toward adipamide during the production of 5-cyanovaleramide (5-CVAM), an important intermediate of herbicide and chemical raw material. Nevertheless, free NHase will face harsh conditions if they are applied directly in industrial processes. In this study, we, therefore, prepared Fe3(PO4)2 hybrid nanoflowers for NHase immobilization based on the protein-inorganic hybrid self-assembly by establishing a novel and facile method.

Hydrogenolysis-Isomerization of Waste Polyolefin Plastics to Multibranched Liquid Alkanes.

Upcycling of waste polyolefin plastics still meets with economic and technological challenges in practice. In this work, the catalytic hydrogenolysis-isomerization of nondegradable polyolefin plastic waste to high-value gasoline, diesel, and light lubricants with highly branched chain is achieved over a bifunctional Rh/Nb O catalyst under relatively mild conditions. Owing to the high efficiency of metallic Rh active sites, the dehydrogenation/hydrogenation of long carbon chains of polyolefins is enhanced.

Modification of nitrile hydratase from Rhodococcus erythropolis CCM2595 by semirational design to enhance its substrate affinity.

Nitrile hydratase (NHase, EC 4.2.1.

Chemical kinetics and promoted Co-immobilization for efficient catalytic carbonylation of ethylene oxide into methyl 3-hydroxypropionate.

The carbonylative transformation of ethylene oxide (EO) into methyl 3-hydroxypropionate (3-HPM) is a key process for the production of 1,3-propanediol (1,3-PDO), which is currently viewed as one of the most promising monomers and intermediates in polyester and pharmaceuticals industry. In this work, a homogeneous reaction system using commercial Co(CO) was first studied for the carbonylation of EO to 3-HPM. The catalytic behavior was related to the electronic environment of N on aromatic rings of ligands, where N with rich electron density induced a stronger coordination with Co center and higher EO transformation.

Boosting the catalytic behavior and stability of a gold catalyst with structure regulated by ceria.

In this work, a series of colloidal gold nanoparticles with controllable sizes were anchored on carbon nanotubes (CNT) for the aerobic oxidation of benzyl alcohol. The intrinsic influence of Au particles on the catalytic behavior was unraveled based on different nanoscale-gold systems. The Au/CNT-A sample with smaller Au sizes deserved a faster reaction rate, mainly resulting from the higher dispersion degree (23.

Low-energy Hemiacetal Dehydrogenation Pathway: Co-production of Gluconic Acid and Green Hydrogen via Glucose Dehydrogenation.

Exploring low-energy reaction pathway of catalytic biomass conversion can lead to wider application and the achievement of sustainability objectives. Since glucose dehydrogenation to gluconic acid and H is a cost-effective alternative to glucose oxidation, this study aims to elucidate its mechanism. The detection of lactone as an intermediate indicates that cyclic glucose reacts directly via its hemiacetal group-ring opening is not involved; that is, cyclic glucose is dehydrogenated to lactone, which is further hydrolyzed to gluconic acid.

Vanadium-catalyzed Oxidative Conversion of Primary Aromatic Alcohols into Amides and Nitriles with Molecular Oxygen.

Amides or nitriles are important building blocks because of the widespread occurrence in chemistry and biology. The development of green and efficient catalytic approaches to introduce nitrogen functionality is highly desired. Herein, a vanadium-based material V-N-C-700 was prepared via a simple and convenient method and employed for liquid-phase catalytic ammoxidation of alcohols with molecular oxygen.

Overcoming Limitations in the Strong Interaction between Pt and Irreducible SiO Enables Efficient and Selective Hydrogenation of Anthracene.

Interactions between metals and oxide supports are crucial in determining catalytic activity, selectivity, and stability. For reducible oxide supported noble metals, a strong metal-support interaction (SMSI) has been widely recognized. Herein we report the intermediate selectivity and stability over an irreducible SiO supported Pt catalyst in the hydrogenation of anthracene that are significantly boosted due to the SMSI-induced formation of intermetallic Pt silicide and Pt-SiO interface.

Intermetallic PdZn nanoparticles catalyze the continuous-flow hydrogenation of alkynols to cis-enols.

Designing highly active and stable lead-free palladium-based catalysts without introducing surfactants and stabilizers is vital for large-scale and high-efficiency manufacturing of cis-enols via continuous-flow semi-hydrogenation of alkynols. Herein, we report an intermetallic PdZn/ZnO catalyst, designed by using the coupling strategy of strong electrostatic adsorption and reactive metal-support interaction, which can be used as a credible alternative to the commercial PdAg/AlO and Lindlar catalysts. Intermetallic PdZn nanoparticles with electron-poor active sites on a Pd/ZnO catalyst significantly boost the thermodynamic selectivity with respect to the mechanistic selectivity and therefore enhance the selectivity towards cis-enols.

Nano-Sized NiO Immobilized on Au/CNT for Benzyl Alcohol Oxidation: Influences of Hybrid Structure and Interface.

Tiny gold nanoparticles were successfully anchored on carbon nanotubes (CNT) with NiO decoration by a two-step synthesis. Characterizations suggested that Ni species in an oxidative state preferred to be highly dispersed on CNT. During the synthesis, in situ reduction by NaBH and thermal treatment in oxidation atmosphere were consequently carried out, causing the formation of Au-Ni-O interfaces and bimetal hybrid structure depending on the Ni/Au atomic ratios.

High Regioselectivity Production of 5-Cyanovaleramide from Adiponitrile by a Novel Nitrile Hydratase Derived from CCM2595.

5-Cyanovaleramide (5-CVAM) is an important intermediate of a herbicide and chemical raw material. Herein, we found a novel nitrile hydratase from the strain CCM2595, exhibiting high regioselectivity with higher substrate specificity toward dinitriles than mononitriles. In the past, the strain was shown to degrade only phenol, hydroxybenzoate, -chlorophenol, aniline, and other aromatic compounds.

Synthesis of Intermetallic Pt-Based Catalysts by Lithium Naphthalenide-Driven Reduction for Selective Hydrogenation of Cinnamaldehyde.

Intermetallic nanoparticles (NPs) with a well-defined atom binding environment and a long-range ordering structure can be used as ideal models to understand their physical and catalytic properties. In this work, several kinds of nanostructured and carbon nanotube (CNT)-supported Pt-based intermetallic compounds (IMCs) have been synthesized by one-step lithium naphthalenide-driven reduction at room temperature without the use of surfactants in light of the reduction potential of metals. In the chemoselective hydrogenation of cinnamaldehyde, the second metal in Pt-M IMCs significantly creates a suitable reaction environment through construction of a good geometric and electronic structure.

Three-Dimensional Heterostructured NiCoP@NiMn-Layered Double Hydroxide Arrays Supported on Ni Foam as a Bifunctional Electrocatalyst for Overall Water Splitting.

Herein, the rational design and preparation of three-dimensional heterostructured NiCoP@NiMn-layered double hydroxide arrays supported on Ni foam (NiCoP@NiMn LDH/NF) is reported as a new bifunctional water-splitting electrocatalyst with high performance. Prepared with facile hydrothermal reactions and phosphorization, the NiCoP@NiMn LDH/NF is simultaneously highly active toward oxygen evolution reaction (OER) (100, 300, and 600 mA cm at overpotentials of 293, 315, and 327 mV, respectively) and hydrogen evolution reaction (HER) (100, 200, and 300 mA cm at overpotentials of 116, 130, and 136 mV, respectively). Interestingly, with cell voltages of 1.

A review on high catalytic efficiency of solid acid catalysts for lignin valorization.

It is imminent to develop renewable resources to replace fossil-derived energies as fossil resources are on the brink of exhaustion. Lignin is one of the major components of lignocellulosic biomass, which is a natural amorphous three-dimensional polymer with abundant C-O bonds and aromatic structure. Hence, valorization of lignin into high value-added liquid fuels and chemicals is regarded as a promising strategy to mitigate fossil resource shortages.

Atomic-Scale Observation of Bimetallic Au-CuO Nanoparticles and Their Interfaces for Activation of CO Molecules.

Supported gold nanoparticles with sizes below 5 nm display attractive catalytic activities for heterogeneous reactions, particularly those promoted by secondary metal (e.g., Cu) because of the well-defined synergy between metal compositions.

Tuning the Acidity of Pt/ CNTs Catalysts for Hydrodeoxygenation of Diphenyl Ether.

We herein present a method for the synthesis of HNbWO6, HNbMoO6, HTaWO6 solid acid nanosheet modified Pt/CNTs. By varying the weight of various solid acid nanosheets, a series of Pt/xHMNO6/CNTs with different solid acid compositions (x = 5, 20 wt%; M = Nb, Ta; N = Mo, W) have been prepared by carbon nanotube pretreatment, protonic exchange, solid acid exfoliation, aggregation and finally Pt particles impregnation. The Pt/xHMNO6/CNTs are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and NH3-temperature programmed desorption.

Template-Preparation of Hollow PtNi Nanostrings as a Bifunctional Electrocatalyst for the Hydrogen Evolution and Oxygen Reduction Reactions.

Designing a highly active, stable and cost-effective electrocatalyst with multiple functionalities toward hydrogen evolution and oxygen reduction applications is crucial for the development of renewable energy sources. Here, the synthesis of hollow PtNi nanostrings via a facile two-step template method is reported. The PtNi nanostrings own Pt-rich rough surfaces, and hollow string-like structure with the structural disorder morphology.

Selective Hydrogenation of Dimethyl Terephthalate to 1,4-Cyclohexane Dicarboxylate by Highly Dispersed Bimetallic Ru-Re/AC Catalysts.

The fabrication of bimetallic catalysts has been taken great focus in the concept of heterogeneous catalysis due to their high efficiency and economic concerns. In this work, a series of bimetallic Ru-Re catalysts were designed and synthesized for the selective hydrogenation of dimethyl terephthalate (DMT) to 1,4-cyclohexane dicarboxylate (DMCD) under mild condition. Characterization techniques including the XRD, TEM, STEM-HAADF EDX elemental mapping, H2-TPR, and XPS were used to study the surface chemical property, the morphology, as well as the catalytic behavior of different samples.

Mechanism of Rhodium(III)-Catalyzed C-H Activation/Annulation of Aromatic Amide with α-Allenol: A Computational Study.

With the help of DFT calculations, the reaction mechanisms of the rhodium(III)-catalyzed C-H activation/annulation between aromatic amide and α-allenol leading to the formation of isoindolinone have been theoretically investigated. Our calculated results show that the catalytic cycle consists of four stages: N-H deprotonation and C-H activation (Stage I), allene insertion, rearrangement and isomerization (Stage II), β-H elimination and enol-keto tautomerism (Stage III), and catalyst regeneration resulting in the five-membered ring product (Stage IV). For stage IV, besides the reaction paths proposed by the experimentalists, i.