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The integration of nanofiltration with catalysis enables high-efficient removal of micropollutants due to its remarkable high selectivity and superior degradation efficacy. Meanwhile, the catalysis-assisted nanofiltration can largely alleviate the issues of inferior low-molecular-weight micropollutants selectivity, membrane fouling and tradeoff limitation. Two different technical routes, catalytic coupled nanofiltration system and catalytic nanofiltration membrane, have been developed based on nanofiltration module and material design for micropollutants separation enhancement. In this review, we first summarize the underlying governing principles of the latest progress of catalysis coupled nanofiltration and catalytic nanofiltration membrane for micropollutants removal. The catalysis and filtration performance of these two routes were initially discussed and compared based on various catalytic oxidation conditions and target substances. We then discussed the corresponding catalytic membrane material innovation and preparation strategies (e.g. coating, bottom-up synthesis, blending, etc.). Finally, we point out the prospects and challenges of catalysis-assisted nanofiltration for micropollutants removal. This review provides directions and guidance for further catalysis-assisted nanofiltration module development and technical industrialization. [ABSTRACT FROM AUTHOR]

Catalyst-loaded activated carbons are the widely used adsorbents to remove H2S for purification of the gas streams. Virgin carbon, single, and mixed catalyst-loaded carbon are used as adsorbents. Their performance of H2S catalytic conversion was studied by evaluating their breakthrough curves in order to investigate the effect of catalyst contents, categories, assistant catalysts, and virgin carbon properties on the H2S adsorption. The effects of gas stream properties on H2S catalytic adsorption are also investigated. The results show the H2S u amount is increased with catalyst contents, and the assistant catalysts can enhance H2S catalytic conversion. NaOH-loaded carbon has better catalytic performance than KOH-loaded carbon with the same contents. Carbons after impregnation keep a relative high-pore volume between 2 and 20 nm, which is beneficial to give full play to the catalysis. The relative humidity and oxygen can enhance the H2S adsorption capacity and play important roles in H2S adsorption. CTC has little effects on the impregnated carbon for H2S catalytic conversion. Carbon impregnated with a specific catalyst can accelerate target substance adsorption and will restrict the pore volume for organics adsorption. [ABSTRACT FROM AUTHOR]

Widespread use of tetracycline (TC) results in its persistent residue and bioaccumulation in aquatic environments, posing a high toxicity to non-target organisms. In this study, a bimetal-doped composite material Ag 3 PO 4 /MIL-101(Fe,Cu) has been designed for the treatment of TC in aqueous solutions. As the molar ratio of Fe/Cu in composite is 1:1, the obtained material AP/MFe 1 Cu 1 is placed in an aqueous environment under visible light irradiation in the presence of 3 mM peroxydisulfate (PDS), which forms a photo-Fenton-like catalytic system that can completely degrade TC (10 mg/L) within 60 min. Further, the degradation rate constant (0.0668 min−1) is 5.66 and 7.34 times higher than that of AP/MFe and AP/MCu, respectively, demonstrating a significant advantage over single metal-doped catalysts. DFT calculations confirm the strong adsorption capacity and activation advantage of PDS on the composite surface. Therefore, the continuous photogenerated electrons (e −) accelerate the activation of PDS and the production of SO 4 •−, resulting in the stripping of abundant photogenerated h + for TC oxidation. Meanwhile, the internal circulation of FeⅢ/FeⅡ and CuⅡ/CuⅢ in composite also greatly enhances the photo-Fenton-like catalytic stability. According to the competitive dynamic experiments, SO 4 •− have the greatest contribution to TC degradation (58.93%), followed by 1O 2 (23.80%). The degradation intermediates (products) identified by high-performance liquid chromatography-mass spectrometry (HPLC/MS) technique indicate the involvement of various processes in TC degradation, such as dehydroxylation, deamination, N-demethylation, and ring opening. Furthermore, as the reaction proceeds, the toxicity of the intermediates produced during TC degradation gradually decreases, which can ensure the safety of the aquatic ecosystem. Overall, this work reveals the synergy mechanism of PDS catalysis and photocatalysis, as well as provides technical support for removal of TC-contaminated wastewater. [Display omitted] • Ag 3 PO 4 /MIL-101(Fe,Cu) shows excellent photo-Fenton-like catalysis under sunlight irradiation. • SO 4.•− behaves greatest contribution to TC degradation (58.93%), followed by 1O 2 (23.80%). • Circulation of FeⅢ/FeⅡ and CuⅡ/CuⅢ within composite enables its recyclable stability. • TC degradation solution shows reduced toxicity to typical aquatic organisms. [ABSTRACT FROM AUTHOR]

In recent years, asymmetric catalysis of ynamides has attracted much attention, but these reactions mostly constructed central chirality, except for a few examples on the synthesis of axially chiral compounds which exclusively relied on noble‐metal catalysis. Herein, a facile access to axially chiral N‐heterocycles enabled by chiral Brønsted acid‐catalyzed 5‐endo‐dig cyclization of ynamides is disclosed, which represents the first metal‐free protocol for the construction of axially chiral compounds from ynamides. This method allows the practical and atom‐economical synthesis of valuable N‐arylindoles in excellent yields with generally excellent enantioselectivities. Moreover, organocatalysts and ligands based on such axially chiral N‐arylindole skeletons are demonstrated to be applicable to asymmetric catalysis. [ABSTRACT FROM AUTHOR]

Nature segregates fundamental tasks such as information storage/transmission and catalysis between two different compound classes (e.g. polynucleotides for replication and folded polyamides for catalysis). This division of labor is likely a product of evolution, raising the question of how simpler systems in which replicators and folded macromolecules co‐exist may emerge in the transition from chemistry to biology. In synthetic systems, achieving co‐existence of replicators and foldamers in a single molecular network remains an unsolved problem. Previous work on dynamic molecular networks has given rise to either self‐replicating fibers or well‐defined foldamer structures (or completely un‐sorted complex systems). We report a system in which two cross‐reactive dithiol (nucleobase‐ and peptide‐based) building blocks self‐sort into a replicator fiber and foldamer that both emerge spontaneously and co‐exist. The self‐sorting behavior remains prevalent across different building block ratios as two phases of emergence occur: replicator growth followed by foldamer formation. This is attributed to the autocatalytic formation of the replicator fiber, followed by enrichment of the system in the remaining building block, which is subsequently incorporated into a foldamer. [ABSTRACT FROM AUTHOR]

Exposing and stabilizing undercoordinated platinum (Pt) sites and therefore optimizing their adsorption to reactive intermediates offers a desirable strategy to develop highly efficient Pt-based electrocatalysts. However, preparation of atomically controllable Pt-based model catalysts to understand the correlation between electronic structure, adsorption energy, and catalytic properties of atomic Pt sites is still challenging. Herein we report the atomically thin two-dimensional PtTe2 nanosheets with well-dispersed single atomic Te vacancies (Te-SAVs) and atomically well-defined undercoordinated Pt sites as a model electrocatalyst. A controlled thermal treatment drives the migration of the Te-SAVs to form thermodynamically stabilized, ordered Te-SAV clusters, which decreases both the density of states of undercoordinated Pt sites around the Fermi level and the interacting orbital volume of Pt sites. As a result, the binding strength of atomically defined Pt active sites to H intermediates is effectively reduced, which renders PtTe2 nanosheets highly active and stable in hydrogen evolution reaction. Precisely regulating Pt catalytic sites is important and challenging. Herein the authors engineer the clustering of single atomic Te vacancies in atomically thin PtTe2 to optimize the electronic structure, adsorption energy, and catalytic performance of atomically defined Pt sites. [ABSTRACT FROM AUTHOR]

The dominated approaches for asymmetric aldol reactions have primarily focused on the aldol carbon–carbon bond‐forming events. Here we postulate and develop a new catalytic strategy that seeks to modulate the reaction thermodynamics and control the product enantioselectivities via post‐aldol processes. Specifically, an NHC catalyst is used to activate a masked enolate substrate (vinyl carbonate) to promote the aldol reaction in a non‐enantioselective manner. This reversible aldol event is subsequently followed by an enantioselective acylative kinetic resolution that is mediated by the same (chiral) NHC catalyst without introducing any additional substance. This post‐aldol process takes care of the enantioselectivity issues and drives the otherwise reversible aldol reaction toward a complete conversion. The acylated aldol products bearing quaternary/tetrasubstituted carbon stereogenic centers are formed in good yields and high optical purities. [ABSTRACT FROM AUTHOR]

An ecofriendly and robust strategy is developed to construct a self‐supported monolithic electrode composed of N‐doped carbon hybridized with bimetallic molybdenum‐tungsten carbide (MoxW2−xC) to form composite nanowires for hydrogen evolution reaction (HER). The hybridization of MoxW2−xC with N‐doped carbon enables effective regulation of the electrocatalytic performance of the composite nanowires, endowing abundant accessible active sites derived from N‐doping and MoxW2−xC incorporation, outstanding conductivity resulting from the N‐doped carbon matrix, and appropriate positioning of the d‐band center with a thermodynamically favorable hydrogen adsorption free energy (ΔGH*) for efficient hydrogen evolution catalysis, which forms a binder‐free 3D self‐supported monolithic electrode with accessible nanopores, desirable chemical compositions and stable composite structure. By modulating the Mo/W ratio, the optimal Mo1.33W0.67C @ NC nanowires on carbon cloth achieve a low overpotential (at a geometric current density of 10 mA cm−2) of 115 and 108 mV and a small Tafel slope of 58.5 and 55.4 mV dec−1 in acidic and alkaline environments, respectively, which can maintain 40 h of stable performance, outperforming most of the reported metal‐carbide‐based HER electrocatalysts. [ABSTRACT FROM AUTHOR]

Ru-Based complexes have advanced the study of molecular water oxidation catalysts (WOCs) both in catalysis and mechanism. The electronic effect has always been considered as an essential factor for the catalyst properties while less attention has been focused on the bite angle effect on water oxidation catalysis. The Ru-bda ([Ru(bda)(pic)2]; bda2− = 2,2′-bipyridine-6,6′-dicarboxylate; pic = 4-picoline) catalyst is one of the most active WOCs and it has a largely distorted octahedral configuration with an O–Ru–O bite angle of 123°. Herein, we replaced the carboxylate (–COO−) groups of bda2− with two methylenesulfonate (–CH2SO3−) groups and prepared a negatively charged ligand, bms2− (2,2′-bipyridine-6,6′-dimethanesulfonate), and the Ru-bms complex [Ru(bms)(pic)2]. The O–Ru–O bite angle changed from 123° in Ru-bda to 84° in Ru-bms, leading to a dramatic influence on the catalytic behavior. Systematic analysis of the reaction intermediates suggested that Ru-bms transformed all the way to Ru-bdavia oxidative decomposition under CeIV-driven water oxidation conditions. [ABSTRACT FROM AUTHOR]

A direct functionalization of the β‐sp3 carbon atom of α‐chloro aldehyde has been developed. The reaction starts with the addition of a carbene catalyst to α‐chloroaldehyde to eventually form the homoenolate intermediate. This overall redox‐neutral process successfully converts the otherwise inert β‐sp3‐carbon atom of the aldehyde substrate to a nucleophilic carbon atom for asymmetric reactions. This study constitutes the first success in activating α‐chloroaldehydes to generate homoenolate intermediates by carbene organic catalysis and shall encourage further explorations in using organic catalysis for transforming inert chemical bonds. [ABSTRACT FROM AUTHOR]

An enantioselective β-carbon amination for enals is disclosed. The nitrogen atom from a protected hydrazine with suitable electronic properties readily behaves as a nucleophile. Addition of the nitrogen nucleophile to a catalytically generated N-heterocyclic-carbene-bound α,β-unsaturated acyl azolium intermediate constructs a new carbon-nitrogen bond asymmetrically. The pyrazolidinone products from our catalytic reactions are common scaffolds in bioactive molecules, and can be easily transformed into useful compounds such as β3-amino-acid derivatives. [ABSTRACT FROM AUTHOR]

Tandem catalytic systems, consisting of ethylene bis(indenyl) zirconium dichloride with two different cocatalysts, alkylaluminum (diethylaluminium chloride or trialkylaluminum) and methylaluminoxane, were employed in preparing branched polyethylene from ethylene as sole monomer. The catalytic system rac-Et(Ind)ZrCl/AlEtCl/MAO exhibited high incorporation (29.0/1000C). The oligomerization and copolymerization reaction conditions in the tandem catalytic system, as well as the different cocatalysts, have effects on the catalytic activity and the properties of the obtained polymer, such as melting temperature, crystallinity, molecular weight and molecular weight distribution. Moreover, the oligomerization reaction condition is the main factor in altering the properties and structures of polyethylene. [ABSTRACT FROM AUTHOR]

The 1D complex [(CuL0.5H2O) ⋅H2O] n ( 1) (H4L=2,2′-bipyridine-3,3′,6,6′-tetracarboxylic acid) undergoes an irreversible thermally triggered single-crystal-to-single-crystal (SCSC) transformation to produce the 3D anhydrous complex [CuL0.5] n ( 2). This SCSC structural transformation was confirmed by single-crystal X-ray diffraction analysis, thermogravimetric (TG) analysis, powder X-ray diffraction (PXRD) patterns, variable-temperature powder X-ray diffraction (VT-PXRD) patterns, and IR spectroscopy. Structural analyses reveal that in complex 2, though the initial 1D chain is still retained as in complex 1, accompanied with the Cu-bound H2O removed and new O(carboxyl)Cu bond forming, the coordination geometries around the CuII ions vary from a distorted trigonal bipyramid to a distorted square pyramid. With the drastic structural transition, significant property changes are observed. Magnetic analyses show prominent changes from antiferromagnetism to weak ferromagnetism due to the new formed Cu1-O-C-O-Cu4 bridge. The catalytic results demonstrate that, even though both solid-state materials present high catalytic activity for the synthesis of 2-imidazolines derivatives and can be reused, the activation temperature of complex 1 is higher than that of complex 2. In addition, a possible pathway for the SCSC structural transformations is proposed. [ABSTRACT FROM AUTHOR]

The atomic layer deposition (ALD)of metal oxides on metal surfacesis of great importance in applications such as microelectronics, corrosionresistance, and catalysis. In this work, Al2O3ALD using trimethylaluminum (TMA) and water was investigated onPd, Pt, Ir, and Cu surfaces by combining in situquartzcrystal microbalance (QCM), quadrupole mass spectroscopy (QMS), andscanning tunneling microscopy (STM) measurements with density functionaltheory (DFT) calculations. These studies revealed that TMA undergoesdissociative chemisorption to form monomethyl aluminum (AlCH3*, the asterisk designates a surface species) on both Pd and Pt,which transform into Al(OH)3* during the subsequent waterexposure. Furthermore, the AlCH3* can further dissociateinto Al* and CH3* on stepped Pt(211). Additional DFT calculationspredicted that Al2O3ALD should proceed on Irfollowing a similar mechanism but not on Cu due to the endothermicityfor TMA dissociation. These predictions were confirmed by in situQCM, QMS, and STM measurements. Our combined theoreticaland experimental study also found that the preferential decorationof low-coordination metal sites, especially after high temperaturetreatment, correlates with the differences in free energy betweenAl2O3ALD on the (111) and stepped (211) surfaces.These insights into Al2O3growth on metal surfacescan guide the future design of advanced metal/metal oxide catalystswith greater durability by protecting the metal against sinteringand dissolution and enhanced selectivity by blocking low-coordinationmetal sites while leaving (111) facets available for catalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • We developed a sensor array based on Co-N-C single-atom nanozymes for colorimetric discrimination of antioxidants. • Under two pH conditions, Co-N-C nanozymes produce different catalytic effects on the reaction between H 2 O 2 and TMB. • Linear discriminant analysis (LDA) was used to successfully analyze the 7 antioxidants. • The sensing strategy had excellent specificity and good application in human serum samples. Here we develop a simple and effective nose/tongue sensor array based on Co-N-C single-atom nanozymes-3,3′,5,5′-tetramethylbenzidine (TMB)-H 2 O 2 for colorimetric discrimination of antioxidants, which makes use of the color reaction of TMB oxidation by H 2 O 2 in two different pH (3.8 and 4.6) environments under the catalysis of Co-N-C nanoenzyme with peroxidase-like activity. Different antioxidants have varying reducing ability to the oxidation products of TMB (oxTMB), thus resulting in differential absorbance and color changes. Linear discriminant analysis (LDA) results indicate that the sensor array successfully identified 7 antioxidants, i.e., glutathione (GSH), ascorbic acid (AA), cysteine (Cys), tannin (TA), Catechin (C), dopamine (DA), and uric acid (UA) in both buffer and even serum samples. Additionally, the performance of the sensor array was validated with antioxidant mixtures, individual antioxidants with different concentrations, and target antioxidants and interfering substances. In general, the versatile sensor array based on Co-N-C single-atom nanozymes provides an excellent strategy for identifying a variety of antioxidants, which exhibits a broad application prospect in medical diagnosis. [ABSTRACT FROM AUTHOR]

Abstract: Poly(ethyleneglycol methacrylate) (PEGDMA) shell was used as a protective layer for the sandwiched gold nanoparticles, which were prepared through the in situ reduction in the HAuCl4 precursor in the presence of (aminopropyl)trimethoxysilane (APS) modified silica/PEGDMA core–shell microspheres. In this process, the silica/PEGDMA core–shell microspheres were afforded by the distillation-precipitation polymerization of the EGDMA monomer on the APS-modified silica particles with the aid of hydrogen-bonding interaction. The gold nanoparticles were formed at the interface between the silica core and the PEGDMA outer layer through the strong coordinate interaction between the gold nanoparticles and the amino groups on the surface of the silica during the reduction in HAuCl4. The sandwiched gold nanoparticles exhibited highly catalytic efficiency and facile recovery with good stability. [Copyright &y& Elsevier]

Glycerol decomposition via a combination of dehydrogenation, C-C bond scission, and C-O bond scission reactions is examined on Pt(111) with periodic Density Functional Theory (DFT) calculations. Building upon a previous study focused on C-C bond scission in glycerol, the current work presents a first analysis of the competition between C-O and C-C bond cleavage in this reaction network. The thermochemistry of various species produced from C-O bond breaking in glycerol dehydrogenation intermediates is estimated using an extension of a previously introduced empirical correlation scheme, with parameters fit to DFT calculations. Brønsted-Evans-Polanyi (BEP) relationships are then used to estimate the kinetics of C-O bond breaking. When combined with the previous results, the thermochemical and kinetic analyses imply that, while C-O bond scission may be competitive with C-C bond scission during the early stages of glycerol dehydrogenation, the overall rates are likely to be very low. Later in the dehydrogenation process, where rates will be much higher, transition states for C-C bond scission involving decarbonylation are much lower in energy than are the corresponding transition states for C-O bond breaking, implying that the selectivity for C-C scission will be high for glycerol decomposition on smooth platinum surfaces. It is anticipated that the correlation schemes described in this work will provide an efficient strategy for estimating thermochemical and kinetic energetics for a variety of elementary bond breaking processes on Pt(111) and may ultimately facilitate computational catalyst design for these and related catalytic processes. [ABSTRACT FROM AUTHOR]

Abstract: In situ FT-IR was employed to investigate CO or/and NO interaction with CuO supported on Ce0.67Zr0.33O2 (hereafter denoted as CZ) catalysts. The physicochemical properties of CuO–CZ were also studied by combination of XRD, TPR and NO+CO activity tests. The results indicated that the dispersed CuO species were the main active components for this reaction. The catalysts showed different activities and selectivities at low and high temperatures, which should be resulted from the reduction of dispersed copper oxide species. This reaction went through different mechanisms at low and high temperatures due to the change of active species. FT-IR results suggested: (1) CO was activated by oxygen originating from CZ support, which led to surface carbonates formation, and partial dispersed CuO was reduced to Cu+ species above 150°C; (2) NO interacted with the dispersed CuO and formed several types of nitrite/nitrate species, whereas crystalline CuO made little contribution to the formation of new NO adsorbates; (3) NO was preferentially adsorbed on CuO–CZ catalysts compared with CO in the reactants mixture. These adsorbed nitrite/nitrate species exhibited different thermal stability and reacted with CO at 250°C. As a result, a possible mechanism was tentatively proposed to approach NO reduction by CO over CuO–CZ catalyst. [Copyright &y& Elsevier]

Abstract: Co-B catalysts were prepared by the chemical reduction of CoCl2 with NaBH4 for hydrogen generation from borohydride hydrolysis. The catalytic properties of the Co-B catalysts were found to be sensitive to the preparation conditions including pH of the NaBH4 solution and mixing manner of the precursors. A Co-B catalyst with a very high catalytic activity was obtained through the formation of a colloidal Co(OH)2 intermediate. The ultra-fine particle size of 10nm accounted for its super activity for hydrogen generation with a maximum rate of 26Lmin−1 g−1 at 30°C. The catalyst also changed the hydrolysis kinetics from zero-order to first-order. [Copyright &y& Elsevier]

Abstract: Borohydrides, a group of compounds with large hydrogen contents, can generate hydrogen readily by their hydrolysis reaction. In this study catalysts based on nickel and cobalt were developed to accelerate the hydrolysis reaction for hydrogen generation. Catalysts in four forms were tested for each metal: fine metal powder, metal salt, metal boride and Raney metal. It was found that the hydrolysis reaction was primary a zero-order reaction under the catalysis of these catalysts. Although cobalt showed higher catalytic activity than nickel in most cases, Raney Ni exhibited almost the same activity as the Raney Co. Among four chemical forms for nickel, Raney Ni demonstrated the best performance. Moreover, Raney catalysts made from alloys of nickel and cobalt showed even higher activity. The reaction on Raney metals was also characterized by a slowdown in hydrogen generation rate at low borohydride concentrations because of a mass transfer limitation. [Copyright &y& Elsevier]

The ability to precisely engineer the doping of sub-nanometer bimetallic clusters offers exciting opportunities for tailoring their catalytic performance with atomic accuracy. However, the fabrication of singly dispersed bimetallic cluster catalysts with atomic-level control of dopants has been a long-standing challenge. Herein, we report a strategy for the controllable synthesis of a precisely doped single cluster catalyst consisting of partially ligand-enveloped Au4Pt2 clusters supported on defective graphene. This creates a bimetal single cluster catalyst (Au4Pt2/G) with exceptional activity for electrochemical nitrogen (N2) reduction. Our mechanistic study reveals that each N2 molecule is activated in the confined region between cluster and graphene. The heteroatom dopant plays an indispensable role in the activation of N2 via an enhanced back donation of electrons to the N2 LUMO. Moreover, besides the heteroatom Pt, the catalytic performance of single cluster catalyst can be further tuned by using Pd in place of Pt as the dopant. The fabrication of singly dispersed metal cluster catalysts with atomic-level control of dopants is a long-standing challenge. Here, the authors report a strategy for the synthesis of a precisely doped single cluster catalyst which shows exceptional activity for electrochemical dinitrogen reduction. [ABSTRACT FROM AUTHOR]

The article presents the use of Ar2I+X− or ArX as the arylating reagent via oxidative addition to nickel(II)-catalyzed C–H arylation.

The cobalt-catalyzed oxidative annulation of N-arylureas and internal alkynes for the construction of indoles is reported. [ABSTRACT FROM AUTHOR]

An abstract of the article "Regioselective Ir(III)-Catalyzed C-H Alkynylation Directed by 7-Azaindoles," by B. Liu and colleagues is presented.

The title reaction allows the synthesis of a wide variety of substituted isoindolinones and isoindoline-1,3-diones in moderate to high yields. [ABSTRACT FROM AUTHOR]

An hypervalent iodine-alkyne reagent bearing tert-butyldiphenylsilyl as protecting group instead of triisopropylsilyl is also compatible but gives lower yields (not shown). [ABSTRACT FROM AUTHOR]

An abstract of the article "Palladium Catalyzed Amide-Oxazoline Directed C-H Acetoxylation of Arenes" by B. Liu and colleagues is presented.

The new method is scalable and tolerates a broad range of functional groups and heteroarenes, providing an efficient access to chlorinated arenes and heteroarenes. [ABSTRACT FROM AUTHOR]

Review: 158 refs. [ABSTRACT FROM AUTHOR]

The scalable protocol for the synthesis of title compounds tolerates various functional groups. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Palladium-Catalyzed Oxidative Olefination of Phenols Bearing Removable Directing Groups under Molecular Oxygen" by B. Liu and others, published in the periodical "Journal of Organic Chemistry" in 2014.

Review: selective oxidations of methane, alcohols and CO over heterogeneous catalysts; 335 refs. [ABSTRACT FROM AUTHOR]

The article highlights the steps of chemical reactions involved in the synthesis of carboxylic esters via palladium-catalyzed direct alkoxycarbonylation of arenes.