Search

Chemical modifiers enhance the efficiency of metal catalysts in numerous applications, but their introduction often involves toxic or expensive precursors and complicates the synthesis. Here, we show that a porous boron nitride carrier can directly modify supported palladium nanoparticles, originating unparalleled performance in the continuous semi‐hydrogenation of alkynes. Analysis of the impact of various structural parameters reveals that using a defective high surface area boron nitride and ensuring a palladium particle size of 4–5 nm is critical for maximizing the specific rate. The combined experimental and theoretical analyses point towards boron incorporation from defects in the support to the palladium subsurface, creating the desired isolated ensembles determining the selectivity. This practical approach highlights the unexplored potential of using tailored carriers for catalyst design. [ABSTRACT FROM AUTHOR]

Chemical modifiers enhance the efficiency of metal catalysts in numerous applications, but their introduction often involves toxic or expensive precursors and complicates the synthesis. Here, we show that a porous boron nitride carrier can directly modify supported palladium nanoparticles, originating unparalleled performance in the continuous semi‐hydrogenation of alkynes. Analysis of the impact of various structural parameters reveals that using a defective high surface area boron nitride and ensuring a palladium particle size of 4–5 nm is critical for maximizing the specific rate. The combined experimental and theoretical analyses point towards boron incorporation from defects in the support to the palladium subsurface, creating the desired isolated ensembles determining the selectivity. This practical approach highlights the unexplored potential of using tailored carriers for catalyst design. [ABSTRACT FROM AUTHOR]

Ultrasmall and homogeneous bimetallic PdxBi nanoalloys are well distributed on a Vulcan carbon support by a facile, low-cost synthetic strategy. The electrochemical activity of the as-prepared homogeneous PdxBi nanoalloy/carbon black nanocomposites is closely related to the content of Bi, revealing their excellent electrocatalytic performance for selective oxidation of monohydric alcohols and vicinal diols in alkali medium. [ABSTRACT FROM AUTHOR]

A 19-year-old Caucasian female with adult-onset Still disease (AOSD) presented for evaluation of an acute clinical decompensation and atypical annular papules and plaques with purpura on the lower extremities. A punch biopsy demonstrated histiocytes with engulfed degenerated erythrocytes and lymphocytes, consistent with hemophagocytic lymphohistiocytosis (HLH). HLH, clinically referred to as macrophage activation syndrome, is a rare complication of AOSD and is life-threatening. Relevant clinical, laboratory, and histologic features of this diagnosis are reviewed. [ABSTRACT FROM AUTHOR]

The application of nitrogen-doped carbons (NDCs) as host materials for single-atom catalysts (SACs) is increasing because of the strong binding affinity of the heteroatom with transition metals. Establishment of the relation between the properties of NDCs, their interaction with metals, and the performance of the resulting catalysts is crucial to guide the design of more effective SACs but has not been critically addressed. Here, a series of NDCs is prepared and studied as hosts for palladium atoms. The amount of nitrogen incorporated primarily depends on the choice of carbon followed by the doping temperature and nitrogen source. Pyridinic and pyrrolic species predominate in all cases, especially at lower doping temperatures. The stabilization of palladium atoms is successful above a critical nitrogen content that depends on the carbon type. Evaluation in the catalytic semi-hydrogenation of 2-methyl-3-butyn-2-ol readily distinguishes the reactivity of single atoms and nanoparticles, which correlates with the electronic properties of palladium described by the average oxidation state. Comparison with SACs based on compositionally-related carbon nitride hosts shows that similarly high stability and tunability of the metal is achievable over NDCs, despite their lower nitrogen contents and greater heterogeneity of coordination sites. [ABSTRACT FROM AUTHOR]

Carbon nitrides integrating macroheterocycles offer unique potential as hosts for stabilizing metal atoms due to their rich electronic structure. To date, only graphitic heptazine-based polymers have been studied. Here, we demonstrate that palladium atoms can be effectively isolated on other carbon nitride scaffolds including linear melem oligomers and poly(triazine/heptazine imides). Increased metal uptake was linked to the larger cavity size and the presence of chloride ions in the polyimide structures. Changing the host structure leads to significant variation in the average oxidation state of the metal, which can be tuned by exchange of the ionic species as evidenced by X-ray photoelectron spectroscopy and supported by density functional theory. Evaluation in the semi-hydrogenation of 2-methyl-3-butyn-2-ol reveals an inverse correlation between the activity and the degree of oxidation of palladium, with oligomers exhibiting the highest activity. These findings provide new mechanistic insights into the influence of the carbon nitride structure on metal stabilization. [ABSTRACT FROM AUTHOR]

Abstract: Graphitic carbon nitride (CN) has been widely regarded as a promising photocatalyst since the discovery of its capability for photocatalytic hydrogen evolution. Herein, we developed a functional CN film on a conductive fluorine‐doped tin oxide (FTO) electrode by using a microprinting‐based direct growth method. Furthermore, the photoelectrochemical performance of the derived CN@FTO film was demonstrated to be enhanced by incorporating molecular cobalt species. The reduced charge transport resistance in the cobalt‐modified CN@FTO films is suggested to accelerate the charge‐carrier transfer rate and thus to improve the performance in photoelectrochemical application. The approach is versatile and can be further optimized by selecting a proper “ink” solution and modifier on various conductive substrates. [ABSTRACT FROM AUTHOR]

The establishment of suitable processes for the conversion of glycerol into allyl alcohol is hindered by the fast deactivation of solid acids in the dehydration of the substrate to acrolein and by the requirement of hydrogen donors to enhance the selectivity of the subsequent reduction step. In this work, silver nanoparticles deposited onto a hierarchical ZSM-5 zeolite are proved to be an effective bifunctional catalyst to conduct the two reactions in the gas phase and in the presence of hydrogen by using a continuous fixed-bed reactor. The acidic function was accomplished by using a ZSM-5 zeolite modified by facile alkaline and acid treatments, which decreased the amount of Lewis acid centers while preserving the amount of Brønsted acid centers, and introduced an auxiliary network of intracrystalline mesopores, thus boosting the selectivity to acrolein (62 %) and the resistance to coking. Upon screening of various metals supported on the aluminosilicate, silver was identified as a superior hydrogenation catalyst, enabling a relatively high activity with >50 % allyl alcohol selectivity. Tuning of the metal loading, temperature, pressure, and contact time led to 15 % yield of allyl alcohol, thus approaching the state-of-the-art transfer hydrogenation systems, and stable behavior for 100 h on stream. Our results highlight the advantage of conducting the two transformations over a bifunctional material rather than over two separate single-function solids. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) exhibits unique properties as a support for single-atom heterogeneous catalysts (SAHCs). Understanding how the synthesis method, carrier properties, and metal identity impact the isolation of metal centers is essential to guide their design. This study compares the effectiveness of direct and postsynthetic routes to prepare SAHCs by incorporating palladium, silver, iridium, platinum, or gold in g-C3N4 of distinct morphology (bulk, mesoporous and exfoliated). The speciation (single atoms, dimers, clusters, or nanoparticles), distribution, and oxidation state of the supported metals are characterized by multiple techniques including extensive use of aberration-corrected electron microscopy. SAHCs are most readily attained via direct approaches applying copolymerizable metal precursors and employing high surface area carriers. In contrast, although post-synthetic routes enable improved control over the metal loading, nanoparticle formation is more prevalent. Comparison of the carrier morphologies also points toward the involvement of defects in stabilizing single atoms. The distinct metal dispersions are rationalized by density functional theory and kinetic Monte Carlo simulations, highlighting the interplay between the adsorption energetics and diffusion kinetics. Evaluation in the continuous three-phase semihydrogenation of 1-hexyne identifies controlling the metal-carrier interaction and exposing the metal sites at the surface layer as key challenges in designing efficient SAHCs. [ABSTRACT FROM AUTHOR]

Amphiphilic block copolymer of sodium polystyrene sulfonate (PSS) and polystyrene(St) was prepared under ultrasonic irradiation. The PSS fragment radicals created during the degradation process was used to initiate the polymerization of styrene(St), and a diblock copolymer of poly(SS-b-St) was obtained when the degradation of PSS and the polymerization of St occurred simultaneously. The block copolymers underwent self assembly in aqueous solution, and formed stable nano micelles with diameters of 95–128 nm. The influence of ultrasonic irradiation on the formation of the block copolymers and micelles were investigated. [ABSTRACT FROM AUTHOR]

Amino acids are the building blocks of proteins and are widely used as important ingredients for other nitrogen‐containing molecules. Here, we report the sustainable production of amino acids from biomass‐derived hydroxy acids with high activity under visible‐light irradiation and mild conditions, using atomic ruthenium‐promoted cadmium sulfide (Ru1/CdS). On a metal basis, the optimized Ru1/CdS exhibits a maximal alanine formation rate of 26.0 molAla ⋅ gRu−1 ⋅ h−1, which is 1.7 times and more than two orders of magnitude higher than that of its nanoparticle counterpart and the conventional thermocatalytic process, respectively. Integrated spectroscopic analysis and density functional theory calculations attribute the high performance of Ru1/CdS to the facilitated charge separation and O−H bond dissociation of the α‐hydroxy group, here of lactic acid. The operando nuclear magnetic resonance further infers a unique "double activation" mechanism of both the CH−OH and CH3−CH−OH structures in lactic acid, which significantly accelerates its photocatalytic amination toward alanine. [ABSTRACT FROM AUTHOR]

The chemical transformation of carbon dioxide (CO2) has been considered as a promising strategy to utilize and further upgrade it to value‐added chemicals, aiming at alleviating global warming. In this regard, sustainable driving forces (i.e., electricity and sunlight) have been introduced to convert CO2 into various chemical feedstocks. Electrocatalytic CO2 reduction reaction (CO2RR) can generate carbonaceous molecules (e.g., formate, CO, hydrocarbons, and alcohols) via multiple‐electron transfer. With the assistance of extra light energy, photoelectrocatalysis effectively improve the kinetics of CO2 conversion, which not only decreases the overpotentials for CO2RR but also enhances the lifespan of photo‐induced carriers for the consecutive catalytic process. Recently, rational‐designed catalysts and advanced characterization techniques have emerged in these fields, which make CO2‐to‐chemicals conversion in a clean and highly‐efficient manner. Herein, this review timely and thoroughly discusses the recent advancements in the practical conversion of CO2 through electro‐ and photoelectrocatalytic technologies in the past 5 years. Furthermore, the recent studies of operando analysis and theoretical calculations are highlighted to gain systematic insights into CO2RR. Finally, the challenges and perspectives in the fields of CO2 (photo)electrocatalysis are outlined for their further development. [ABSTRACT FROM AUTHOR]

• 2D g-C 3 N 4 nanosheet was fabricated by the supramolecular assembly approach. • Assembled 2D g-C 3 N 4 photocatalyst demonstrates enhanced HER performance. • 2D nanostructure accelerates charge transport and solar-to-hydrogen efficiency. • Ultrafast spectroscopy reveals charge carrier dynamics in 2D g-C 3 N 4 nanosheets. Two-dimensional graphitic carbon nitride (2D g-C 3 N 4) nanostructures have been the focus of substantial research interest recently owing to their promising photoactive properties for use in solar-to-fuel conversion. However, the synthesis of 2D g-C 3 N 4 nanomaterials remains a significant challenge. Here we successfully synthesized 2D g-C 3 N 4 nanosheets via a supramolecular chemistry approach. 2D g-C 3 N 4 nanostructures not only enhance the visible light-harvesting property but also provide more catalytic sites for improved hydrogen evolution reaction (HER). More importantly, we describe experimental findings concerning the dynamics of charge and energy transfer by using ultrafast spectroscopy in combination with in-situ electron spin resonance (ESR) characterization. The mechanistic investigation reveals that the introduction of a benzene-substituted melamine motif can remarkably accelerate the electron-hole separation and suppress the recombination of photogenerated charge carriers. The carrier separation dynamics is expected to be tailored by engineering the surface and morphology of g-C 3 N 4 , which favors enhanced solar photocatalytic HER efficiency. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Solar‐driven cross‐coupling reactions by dual nickel/photocatalysis under mild conditions have received considerable attention. However, the existing photo/nickel dual catalytic cross‐coupling reactions require the addition of expensive photosensitizers and organic ligands, and the catalytic activity is inadequate. Herein, we report a nickel single‐atom heterogeneous catalyst supported on mesoporous carbon nitride for photocatalytic C—O coupling reaction between 4‐bromobenzonitrile and ethanol, affording 4‐ethoxybenzonitrile in excellent yield compared to a semi‐heterogeneous catalytic system. The catalytic system exhibits a broad substrate scope including ketones, aldehydes, esters, and amides. This work presents a simple and cost‐effective strategy for anchoring metal single atoms onto carbon nitride, providing a new platform for enabling high‐performance photocatalytic production of aryl ether compounds. [ABSTRACT FROM AUTHOR]

Rational design and controllable synthesis of efficient electrocatalysts for water oxidation is of significant importance for the development of promising energy conversion systems, in particular integrated photoelectrochemical water splitting devices. Cobalt oxide (Co 3 O 4) nanostructures with mixed valences (II,III) have been regarded as promising electrocatalysts for the oxygen evolution reaction (OER). They are able to promote catalytic support of OER but with only modest activity. Here, we demonstrate that the OER performance of cubic Co 3 O 4 electrocatalyst is obviously improved when they are anchored on delaminated two-dimensional (2D) Ti 3 C 2 MXene nanosheets. Upon activation the overpotential of the hybrid catalyst delivers 300 mV at a current density of 10 mA cm−2 in basic solutions, which is remarkably lower than those of Ti 3 C 2 MXene and Co 3 O 4 nanocubes. The strong interfacial electrostatic interactions between two components contribute to the exceptional catalytic performance and stability. The enhanced OER activity and facile synthesis make these Co 3 O 4 nanocubes-decorated ultrathin 2D Ti 3 C 2 MXene nanosheets useful for constructing efficient and stable electrodes for high-performance electrochemical water splitting. [ABSTRACT FROM AUTHOR]

The development of methods for selective cleavage reactions of thermodynamically stable C−C/C=C bonds in a green manner is a challenging research field which is largely unexplored. Herein, we present a heterogeneous Fe−N−C catalyst with highly dispersed iron centers that allows for the oxidative C−C/C=C bond cleavage of amines, secondary alcohols, ketones, and olefins in the presence of air (O2) and water (H2O). Mechanistic studies reveal the presence of water to be essential for the performance of the Fe−N−C system, boosting the product yield from <1 % to >90 %. Combined spectroscopic characterizations and control experiments suggest the singlet 1O2 and hydroxide species generated from O2 and H2O, respectively, take selectively part in the C−C bond cleavage. The broad applicability (>40 examples) even for complex drugs as well as high activity, selectivity, and durability under comparably mild conditions highlight this unique catalytic system. [ABSTRACT FROM AUTHOR]

The development of methods for selective cleavage reactions of thermodynamically stable C−C/C=C bonds in a green manner is a challenging research field which is largely unexplored. Herein, we present a heterogeneous Fe−N−C catalyst with highly dispersed iron centers that allows for the oxidative C−C/C=C bond cleavage of amines, secondary alcohols, ketones, and olefins in the presence of air (O2) and water (H2O). Mechanistic studies reveal the presence of water to be essential for the performance of the Fe−N−C system, boosting the product yield from <1 % to >90 %. Combined spectroscopic characterizations and control experiments suggest the singlet 1O2 and hydroxide species generated from O2 and H2O, respectively, take selectively part in the C−C bond cleavage. The broad applicability (>40 examples) even for complex drugs as well as high activity, selectivity, and durability under comparably mild conditions highlight this unique catalytic system. [ABSTRACT FROM AUTHOR]

Bimetallic interstitial compounds with unique geometric properties have attracted increasing attention in energy-related fields and diverse chemical transformations. Current synthesis of these compounds generally involves at least one wet-chemistry step with the use of various solvents to prepare the bimetallic precursors, and no universal protocols for different compositions are yet available. Herein, a novel synthetic strategy toward a platform of nickel-based bimetallic interstitial compounds with the formula MNi3Cx, M = Zn, In, and Ga, was developed based on a straightforward solid-state transformation, i.e., simply annealing the hydroxides of the respective metals in the presence of different carbon precursors (cyanamide, dicyandiamide, melamine, and urea) in a hydrogen stream. The key process parameters influencing the compositions of the final products are studied and the formation mechanism is discussed based on advanced characterization techniques. Powder X-ray diffraction reveals MNi3Cx as a single phase and electron microscopy shows that the MNi3Cx particles are covered with N-doped carbon shells. Extrapolation to other bimetallic interstitial compounds failed when following the above protocol, and the successful examples are linked to the formation of the corresponding bimetallic alloys in the absence of carbon precursors. When evaluated for the selective hydrogenation of dimethyl oxalate, both InNi3C0.5 and ZnNi3C0.7 show comparable high activity. While ZnNi3C0.7 delivers the highest selectivity for methyl glycolate, tunable methyl glycolate and ethylene glycol are formed on InNi3C0.5. In general, this facile solvent-free strategy affords an interesting scaffold to fabricate more advanced multi-metallic interstitial compounds with broad applications. [ABSTRACT FROM AUTHOR]

Regulating the coordination environment of single‐atom sites is of high necessity to promote the catalytic performances of the photocatalysts. Herein, the preparation of atomically dispersed Co‐Ag dual‐metal sites anchored on P‐doped carbon nitride (Co1Ag1‐PCN) via supramolecular and solvothermal approaches is reported, which demonstrates desirable performance for photocatalytic H2 evolution from water splitting. The optimal Co1Ag1‐PCN catalyst achieves a remarkable hydrogen production rate of 1190 µmol g−1 h−1 with an apparent quantum yield (AQY) of 1.49% at 365 nm, superior to most of the newly reported metal‐N‐coordinated photocatalysts. Systematic experimental characterizations and density functional theoretic studies attribute the enhanced photocatalytic activity to the synergistic effect of Co‐Ag dual sites with exclusive coordination configuration of Co‐N6 and Ag‐N2C2, which enhances the charge density and promotes oriented electrons transport to the metal centers with reduced free energy barriers by facilitating the formation of H* intermediates as the key step in hydrogen evolution. This study reveals a versatile strategy to tailor the electronic structures of dual‐metal sites with synergies by engineering the neighboring coordination environment. [ABSTRACT FROM AUTHOR]

In article number 1605785, Javier Pérez‐Ramírez and co‐workers investigate the synthesis of single‐atom heterogeneous catalysts based on precious metals and using graphitic carbon nitride as the carrier. Advanced characterization and simulations reveal the impact of the carrier properties, and of the metal identity and method of introduction on the speciation. Controlling the metal‐carrier interaction and exposing the reactive metal centers are key for maximizing the potential of these materials. [ABSTRACT FROM AUTHOR]

Controlling the structure sensitivity of catalyzed reactions over metals is central to developing atom‐efficient chemical processes. Approaching the minimum ensemble size, the properties enter a non‐scalable regime in which each atom counts. Almost all trends in this ultra‐small frontier derive from surface science approaches using model systems, because of both synthetic and analytical challenges. Exploiting the unique coordination chemistry of carbon nitride, we discriminate through experiments and simulations the interplay between the geometry, electronic structure, and reactivity of palladium atoms, dimers, and trimers. Catalytic tests evidence application‐dependent requirements of the active ensemble. In the semi‐hydrogenation of alkynes, the nuclearity primarily impacts activity, whereas the selectivity and stability are affected in Suzuki coupling. This powerful approach will provide practical insights into the design of heterogeneous catalysts comprising well‐defined numbers of atoms. [ABSTRACT FROM AUTHOR]

Controlling the structure sensitivity of catalyzed reactions over metals is central to developing atom‐efficient chemical processes. Approaching the minimum ensemble size, the properties enter a non‐scalable regime in which each atom counts. Almost all trends in this ultra‐small frontier derive from surface science approaches using model systems, because of both synthetic and analytical challenges. Exploiting the unique coordination chemistry of carbon nitride, we discriminate through experiments and simulations the interplay between the geometry, electronic structure, and reactivity of palladium atoms, dimers, and trimers. Catalytic tests evidence application‐dependent requirements of the active ensemble. In the semi‐hydrogenation of alkynes, the nuclearity primarily impacts activity, whereas the selectivity and stability are affected in Suzuki coupling. This powerful approach will provide practical insights into the design of heterogeneous catalysts comprising well‐defined numbers of atoms. [ABSTRACT FROM AUTHOR]

Metal‐organic framework catalysts bring new opportunities for CO2 electrocatalysis. Herein, we first conduct density‐functional theory calculations and predict that Co‐based porphyrin porous organic layers (Co‐PPOLs) exhibit good activity for CO2 conversion because of the low *CO adsorption energy at Co‐N4 sites, which facilitates *CO desorption and CO formation. Then, we prepare two‐dimensional Co‐PPOLs with exclusive Co‐N4 sites through a facile surfactant‐assisted bottom‐up method. The ultrathin feature ensures the exposure of catalytic centers. Together with large specific area, high electrical conductivity and CO2 adsorption capability, Co‐PPOLs achieve a peak faradaic efficiency for CO production (FECO=94.2 %) at a moderate potential in CO2 electroreduction, accompanied with good stability. Moreover, Co‐PPOLs reach an industrial‐level current above 200 mA in a membrane electrode assembly reactor, and maintain near‐unity CO selectivity (FECO>90 %) over 20 h in CO2 electrolysis. [ABSTRACT FROM AUTHOR]

Metal‐organic framework catalysts bring new opportunities for CO2 electrocatalysis. Herein, we first conduct density‐functional theory calculations and predict that Co‐based porphyrin porous organic layers (Co‐PPOLs) exhibit good activity for CO2 conversion because of the low *CO adsorption energy at Co‐N4 sites, which facilitates *CO desorption and CO formation. Then, we prepare two‐dimensional Co‐PPOLs with exclusive Co‐N4 sites through a facile surfactant‐assisted bottom‐up method. The ultrathin feature ensures the exposure of catalytic centers. Together with large specific area, high electrical conductivity and CO2 adsorption capability, Co‐PPOLs achieve a peak faradaic efficiency for CO production (FECO=94.2 %) at a moderate potential in CO2 electroreduction, accompanied with good stability. Moreover, Co‐PPOLs reach an industrial‐level current above 200 mA in a membrane electrode assembly reactor, and maintain near‐unity CO selectivity (FECO>90 %) over 20 h in CO2 electrolysis. [ABSTRACT FROM AUTHOR]

Research related to lignin valorization into fine chemicals is an extremely demanding task due to the wide distribution and low economic value of depolymerization products. Benzoic acid derivatives (BADs) are the final products of the selective oxidation of the lignin side chain (i.e., p-hydroxybenzoic acid, vanillic acid, syringic acid, and benzoic acid), with favorable processibility functionality, showing great potential in the synthesis of active pharmaceutical ingredients (APIs) containing ester and carbonyl groups. Herein, this tutorial review presents our views on lignin utilization, especially using lignin-based benzoic acid derivatives (LBADs) as raw materials for the synthesis of APIs, with the aim of providing a greener, more eco-friendly approach for providing a sustainable route for the production of APIs. We first introduce the conversion of lignin or lignin platform compounds via the oxidative cleavage of C–C and C–O bonds to LBADs. Subsequently, focusing on the functional group modification strategy for the conversion of LBADs, we raise a "Demand Orientation" concept and several typical API synthesis routes. This tutorial review provides green production routes from LBADs in six instances (i.e., trimebutine, aniracetam, diethylstilbestrol, dopamine, acetaminophen, oxybuprocaine). Finally, several others APIs from LBADs via theoretically feasible and sustainable routes are proposed. Some personal perspectives are provided to highlight the opportunities within this attractive field. [ABSTRACT FROM AUTHOR]

The rational design of economic and high‐performance electrocatalytic water‐splitting systems is of great significance for energy and environmental sustainability. Developing a sustainable energy conversion‐assisted electrocatalytic process provides a promising novel approach to effectively boost its performance. Herein, a self‐sustained water‐splitting system originated from the heterostructure of perovskite oxide with 2D Ti3C2Tx MXene on Ni foam (La1‐xSrxCoO3/Ti3C2Tx MXene/Ni) that shows high activity for solar‐powered water evaporation and simultaneous electrocatalytic water splitting is presented. The all‐in‐one interfacial electrocatalyst exhibits highly improved oxygen evolution reaction (OER) performance with a low overpotential of 279 mV at 10 mA cm−2 and a small Tafel slope of 74.3 mV dec−1, superior to previously reported perovskite oxide‐based electrocatalysts. Density functional theory calculations reveal that the integration of La0.9Sr0.1CoO3 with Ti3C2Tx MXene can lower the energy barrier for the electron transfer and decrease the OER overpotential, while COMSOL simulations unveil that interfacial solar evaporation could induce OH− enrichment near the catalyst surfaces and enhance the convection flow above the catalysts to remove the generated gas, remarkably accelerating the kinetics of electrocatalytic water splitting. [ABSTRACT FROM AUTHOR]

The shape of the carriers has a profound impact on the catalytic performance of metal‐supported catalysts. Herein, ZrO2 of different shapes (nanorods‐like, spherical or irregular nanoparticles, demoted as RZ, SPZ, and IPZ, respectively) are adopted to disperse Ni species to assess the shape effects on the catalytic performance in dry reforming of methane. To this end, the fresh and spent catalysts are thoroughly characterized by multiple techniques including N2 sorption, powder X‐ray diffraction, temperature‐programmed reduction with H2, thermogravimetric analyses, transmission electron microscopy, Raman and X‐ray photoelectron spectroscopies. It is revealed that the reducibility of NiO species follows the orders of Ni/RZ

The donor-acceptor (D-A) interactions between the triazine ring unit and adjacent substituents is one of the decisive factors that affect the performance of triazine-based conjugated polymer photocatalysts. Herein, we design and synthesize novel conjugated polymers by introducing electron-drawing 1,3,4-oxadiazole units into 1,3,5-triazine-based π-conjugated skeletons for photocatalytic hydrogen production. Compared with the bulk polymer, the modified photocatalysts show extended visible light harvesting and boosted charge separation. Notably, under the irradiation of full-spectrum solar light, as-synthesized polymer with bi-1,3,4-oxadiazole linkage (denoted as TCP-BOXD) shows a highly improved hydrogen-evolving rate up to 3000 μmol g−1 h−1. Furthermore, DFT calculation reveals that N atoms in the introduced 1,3,4-oxadiazole unit, coupled with those in the triazine ring, act as synergistic bi-active sites for superior photocatalytic hydrogen production. Our findings may help the rational design and controllable synthesis of novel triazine-based conjugated polymers for photocatalysis. [Display omitted] • Novel triazine-based conjugated polymer photocatalysts were synthesized. • π-conjugated polymers show extended visible light harvesting and boosted charge separation. • The modified polymer shows a highly improved hydrogen-evolving rate up to 3000 μmol g−1 h−1. • DFT calculations reveal that N atoms in the introduced unit act as a synergistic active site. [ABSTRACT FROM AUTHOR]

As the "fourth-largest energy source" and the "only renewable organic carbon source", biomass and its derived platform molecules (BDPMs) are widely used for selective upgrading to high-value-added chemicals and fuels, which can alleviate the energy crisis caused by the shortage of traditional fossil fuels. Electrocatalysis is emerging as a promising "biorefinery technology" for BDPM valorization, in which various high-value-added chemicals and fuels can be produced under green and mild conditions. However, the development of electrocatalytic upgrading of BDPMs is hugely lopsided due to a limited understanding of the reaction mechanisms. Herein, we comprehensively review the electrocatalytic upgrade of the top 14 BDPMs (classified into three main groups: alcohols, furans, and carboxylic acids) into high value-added chemicals and fuels, concentrating on the reaction pathways and the mechanisms. Thereafter, we emphasize the recent development of advanced electrode materials and focus on the principles for enhanced electrochemical activity and product selectivity. Afterward, a detailed analysis of advanced electrocatalyst synthesis and modification strategies is described to inspire more research attention and bring forward the practical application of the technique. Finally, we highlight the opportunities, identify the challenges, and propose perspectives for the future development of this flourishing field. [ABSTRACT FROM AUTHOR]

Solar‐driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon‐nitride‐supported palladium single‐atom heterogeneous catalyst with unparalleled performance in photocatalytic water‐donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic‐labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ‐generated protons from water splitting under visible‐light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites. [ABSTRACT FROM AUTHOR]

Solar‐driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon‐nitride‐supported palladium single‐atom heterogeneous catalyst with unparalleled performance in photocatalytic water‐donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic‐labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ‐generated protons from water splitting under visible‐light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites. [ABSTRACT FROM AUTHOR]

Nitrogen-doped carbons (NC) and carbon nitride (C 3 N 4) belong to the two fundamental pillars of functionalized carbon materials that have broad applications in different fields. The synthesis of NC and C 3 N 4 often starts from different precursors, and a general approach that can offer both architectures is still highly sought. Herein, a facile Triton X-100-assisted copolymerization-carbonization strategy is reported to fulfill this task. By moderating the weight ratios of Triton X-100 and several conventional precursors of C 3 N 4 (e.g., dicyandiamide, urea, and cyanamide), a series of both types of N-functionalized carbons with controllable N dopants is successfully afforded. The yielded solids transform from graphitic C 3 N 4 with low surface areas to porous NC when the weight ratio reaches the critical values. This phenomenon might be attributed to the intensified copolymerization between the intermediates of both starting precursors during the carbonization, resulting in increased oxygen content and decreased N:C ratio in the products. Both the bulk and activated carbon-supported materials are then designed and used as metal-free catalysts in the dehydrochlorination of ethylene dichloride, a key reaction in polyvinyl chloride manufacture. It is found that NC is significantly more active than C 3 N 4 , but the corresponding supported catalysts exhibit an opposing trend. The structure-activity correlations suggest both the number of different N defects and the surface areas might play key roles in determining the dehydrochlorination chemistry. Tailor synthesis of C 3 N 4 and N-doped carbons with controllable N defects was enabled by a newly developed approach through co-pyrolysis of Triton X-100 and conventional C 3 N 4 precursors. [Display omitted] [ABSTRACT FROM AUTHOR]

Selective conversion of specific functional groups to desired products is highly important but still challenging in industrial catalytic processes. The adsorption state of surface species is the key factor in modulating the conversion of functional groups, which is correspondingly determined by the uniformity of active sites. However, the non‐identical number of metal atoms, geometric shape, and morphology of conventional nanometer‐sized metal particles/clusters normally lead to the non‐uniform active sites with diverse geometric configurations and local coordination environments, which causes the distinct adsorption states of surface species. Hence, it is highly desired to modulate the homogeneity of the active sites so that the catalytic transformations can be better confined to the desired direction. In this review, the construction strategies and characterization techniques of the uniform active sites that are atomically dispersed on various supports are examined. In particular, their unique behavior in boosting the catalytic performance in various chemical transformations is discussed, including selective hydrogenation, selective oxidation, Suzuki coupling, and other catalytic reactions. In addition, the dynamic evolution of the active sites under reaction conditions and the industrial utilization of the single‐atom catalysts are highlighted. Finally, the current challenges and frontiers are identified, and the perspectives on this flourishing field is provided. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ptδ+ species with high positive charge was identified as the most active sites. • An efficient catalyst, 0.38Pt/CeO 2 , was designed after studying the structure and performance relationship. • Hydrogen-borrowing amination can be carried out at only 80 °C with the yield of target product of 90 %. The chemical state of metallic site is crucial for the performance of supported catalysts. Due to the difference of metal-support interaction, the chemical states of the supported metallic species are usually various and identifying the most active site is therefore very important for the design of efficient catalysts. In this work, a superior Ptδ+ species with high positive charge is identified as the active site in the hydrogen-borrowing amination of cyclopentanol with cyclopentylamine via structure and performance relationship study over Pt/CeO 2 catalyst. It is found that the lower Pt loaded catalyst (0.74 %Pt/CeO 2) has much higher activity than that of the higher Pt loaded one (1.5 %Pt/CeO 2). In-situ CO-DRIFTs and XANES studies show that Pt in 0.74 %Pt/CeO 2 catalyst has higher positive charge, favoring the dehydrogenation of cyclopentanol to cyclopentanone, the rate-determining step in the whole reaction. Furthermore, a 0.38 %Pt/CeO 2 catalyst was prepared, which shows excellent performance at lower temperature (80 °C), the mildest reaction conditions investigated up to now. This work provides a new sight in the design of excellent catalysts for the hydrogen-borrowing amination under mild reaction conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly dispersed Ru nanoparticles were loaded on three kinds of CeO 2 with different morphologies (rod, cube, and octahedron). • The Ru/CeO 2 -R (rod) catalyst possesses much more oxygen vacancies and Ru0 than other Ru/CeO 2 samples. • The Ru/CeO 2 -R (rod) catalyst shows high activity and excellent stability for the N -alkylation of amines with alcohols via the transfer hydrogenation path. • The Ru nanoparticles with a metallic state promote the dehydrogenation of the hydroxyl group and hydrogenation of imines. • CeO 2 -R with rich oxygen vacancies facilitates the adsorption and activation of benzyl alcohol. Efficient and selective N -alkylation of amines with alcohols via transfer hydrogenation is of great significance but extremely challenging. Here, we report the production of N –benzylaniline (BZA) from benzyl alcohol and aniline over various fine-shaped Ru/CeO 2 catalysts. The Ru/CeO 2 –R (rod) catalyst exhibits the highest catalytic activity among all catalysts, in which the yield of BZA reaches up to 88% with complete conversion, significantly higher than that of Ru/CeO 2 -C (cube, 52%) and Ru/CeO 2 -O (octahedron, 32%). Extensive experimental investigations disclose that Ru nanoparticles with a metallic state promote the dehydrogenation of the hydroxyl group and hydrogenation of imines, while the CeO 2 –R with rich oxygen vacancies facilitates the adsorption and activation of reactants. Furthermore, kinetic studies and time-resolved operando dual-beam Fourier transform infrared spectroscopy analysis confirms the transfer hydrogenation pathway, in which the benzyl alcohol is firstly dehydrogenated to benzaldehyde, followed by spontaneously reacting with aniline, and finally transforms into the N -benzylaniline rapidly. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel strategy for the direct production of aniline from alcohols was developed. • Up to 80% yield of desired aniline was achieved over Pt/CeO 2 in fixed bed reactor. • Pt/CeO 2 exhibited excellent stability without deactivation within tested 100 h. • The excellent activity of Pt/CeO 2 catalyst is attributed to its suitable basic property and smaller Pt particle size. Anilines are essential building blocks and widely used in the synthesis of pharmaceuticals, agrochemicals, polymers and hetercycles, but its production is highly relied on traditional methods with petroleum-based chemicals as basis. Herein, a novel dehydrogenation-amination-dehydrogenation strategy is developed for the first time to the synthesis of aniline from cyclohexanol over various Pt-based catalysts. It is shown that Pt/CeO 2 catalyst has the best performance. Comprehensive studies find that in the three catalytic steps, i. e., the dehydrogenation of cyclohexanol, the amination of cyclohexanone and the dehydrogenation of cyclohexylamine, the dehydrogenation of cyclohexylamine to aniline is the rate-determining step. Structure-performance relationship studies show that compared with Pt/C and Pt/Al 2 O 3 catalysts, the excellent performance of Pt/CeO 2 is originated from its suitable basic property and smaller Pt particle size, which are more favorable for the dehydrogenation steps. Meanwhile, 100 h long-term stability is achieved and this strategy is also extended to other alcohol. This is a new strategy for the construction of aniline from simple alcohol and will provide a new and promising direction for the synthesis of aromatic amine with the features of cheapness, green and sustainability. [ABSTRACT FROM AUTHOR]

• Modified g-C 3 N 4 nanostructures was fabricated by a preorganization approach. • g-C 3 N 4 photocatalysts demonstrate improved degradation and hydrogen production. • Nanostructure engineering accelerates charge carrier dynamics. • Tunable band structure and high-performance solar photocatalysis are achieved. Pristine graphitic carbon nitride (g-C 3 N 4) suffers from poor photocatalytic activity due to its limited light adsorption, small specific surface area and feasible recombination of photogenerated charge carriers. One practical approach to solve the problem of low solar-to-hydrogen efficiency is nanostructuring the morphology of g-C 3 N 4 to enhance its light-harvesting property and boost the rate of charge-carrier transportation. Here, we present a strategy to optimize the textural properties and catalytic performance of g-C 3 N 4 via using oxamide (OA) as a chemical modifier in the precursor solution, which significantly make the light absorption edge shift from 440 to 650 nm. Moreover, the nanostructure of the resultant g-C 3 N 4 can be easily tuned with increasing the amount of oxamide. The morphological features of g-C 3 N 4 materials change from sheet-like structure to tubular structure, porous nanotube and eventually interconnected porous sheet. More interestingly, the unique g-C 3 N 4 nanostructure offers advantages of a broader solar absorption spectrum and accelerates charge carrier dynamics that are favorable for advancing photocatalytic performance. The findings provide insightful information that can be used to understand the structure-property relationship in g-C 3 N 4 nanostructures for improved solar-to-fuel conversion. [ABSTRACT FROM AUTHOR]

Introduction: Reactive oxygen species (ROS) are major contributors to cancer and involved in numerous tumor proliferation signaling pathways. Mitochondria are the major ROS-producing organelles, and ROS are produced from the synthesis of adenosine triphosphate and cell metabolism. Methods: A novel mitochondria-targeted peptide, namely KRSH, was synthesized and characterized. KRSH consists of four amino acids; lysine and arginine contain positively charged groups that help KRSH target the mitochondria, while tyrosine and cysteine neutralize excessive endogenous ROS, thereby inhibiting tumorigenesis. Results: The results indicated that KRSH is specifically inhibiting the growth of HeLa and MCF-7 cancer cell lines. However, MCF10A cells can resist the effects of KRSH even in a relative higher concentration. The dichloro-dihydro-fluorescein diacetate and MitoSOXTM Red assay suggested that KRSH drastically decreased the level of ROS in cancer cells. The mitochondrial depolarization assay indicated that treatment with KRSH at a dose of 50 nM may decrease the mitochondrial membrane potential leading to apoptosis of HeLa and MCF-7 cells. Conclusion: In other studies, investigating rat liver mitochondria, the uptake of KRSH may reach 80% compared with that for mitoquinone. Therefore, KRSH was designed as a superior peptide antioxidant and a mitochondria-targeting anticancer agent. [ABSTRACT FROM AUTHOR]

[Display omitted] • Double-modified g-C 3 N 4 -Cl-5H demonstrated highest benzaldehyde production (1.74 mg h−1) under sunlight. • Superoxide radical acted as the most critical active species via the inhibitor assays and product composition analysis. • Attachment sites of doped Cl on g-C 3 N 4 were calculated by comparing the density of states with the actual band gap. • Ammonium chloride provided Cl elements while acting as a porous-directing agent for the material. Lignin has become the largest renewable aromatic resource, and photocatalytic breaking of lignin linkage bonds has emerged as a promising green oxidation technology initiated by solar energy at room temperature. Wherein, carbon nitride (g-C 3 N 4) photo-cracking of lignin has the advantage of stability and reusability (no photo-corrosion), but is inefficient compared to conventional metal sulfides. In this work, g-C 3 N 4 was dual-modified with Cl doping and high-temperature oxidation, to maximum retain the π-π conjugation that can absorb the benzene ring structure in lignin. The inhibitor experiments and product composition analysis indicated that superoxide radicals acted as the most crucial active species, which was 4 times higher than that of g-C 3 N 4. The attachment sites of doped Cl on carbon nitride were calculated by comparing the density of states with the actual band gap. The as-fabricated g-C 3 N 4 -Cl-A5 photocatalyst showed a longer carrier lifetime and higher oxygen adsorption capacity and demonstrated excellent benzaldehyde production (1.74 mg h−1) from the lignin model under sunlight. The work provides insights into the enhanced superoxide radicals generation via photocatalysis and guidance for the selective breaking of lignin β-O-4 bonds. [ABSTRACT FROM AUTHOR]

5-Methylfurfural (MF) is a critical commodity chemical used as food additive and synthetic intermediate. Opening a sustainable route towards highly selective synthesis of MF from 5-hydroxymethylfurfural (HMF) is of great significance, but has demonstrated extremely challenging. Herein, we report an efficient process for the selective production of MF from HMF over an anatase-supported gold catalyst (Au/a-TiO 2). During the hydrogenolysis of HMF, the desired C O bond is maintained and MF can be obtained in a high yield of 83.1 %, exhibiting excellent stability both in batch and flow operation. A combination of experimental and theoretical analyses attribute the superior performance of Au/a-TiO 2 to the synergistic effect of limited H access, low adsorption of reactants, and avoiding condensation, driven by the high concentration of oxygen vacancies in the support. This study highlights a novel approach of tailoring the coverage of active species for the selective transformation of renewable compounds into high-value-added chemicals. [Display omitted] • Selective production of MF from HMF via direct hydrogenolysis of the hydroxyl group using the Au/a-TiO 2 catalyst. • The C=O functional group was preserved under reductive conditions and MF can be obtained in a high yield of 83.1%. • The Au/a-TiO 2 catalyst shows high activity, remarkable selectivity, and excellent stability both in batch and flow operation. • The synergistic effect of limited H access, low adsorption of reactants, high concentration of oxygen vacancies. • This study paves the way for the design of new bifunctional catalysts toward selective hydrogenolysis of biomass. [ABSTRACT FROM AUTHOR]

Photocatalytic lignin depolymerization emerges as a sustainable and cost-competitive strategy to produce low-molecular-weight aromatic chemicals from renewable resources. Significant efforts have been devoted to engineering C−C bond cleavage photocatalysts with diverse compositional and morphologic characteristics in the past decade. We herein present a facile photocatalytic strategy of promoting C−C bond cleavage in lignin models to achieve high-yield aromatic monomers over triazine-heptazine-based carbon nitride heterojunctions, exceeding the triazine- or heptazine-based counterparts. Mechanistic investigations reveal that the photo-excited electron and hole synergistically trigger the C−C bond cleavage. A combination of experimental results and theoretical calculations confirms that the improved photocatalytic performance is primarily attributed to the accelerated charge carriers separation and migration induced by the built-in electric field at the heterojunction interface, and the facilitated C β -radical generation. These findings highlight the effectiveness of interfacial engineering of intramolecular heterostructures towards the rational promotion of photocatalytic cleavage of C−C bond in lignin models. [Display omitted] • Carbon nitride heterojunctions are synthesized via NaCl/KCl-induced polymerization. • High selectivity of photocatalytic C−C bond cleavage in lignin models is achieved. • Excellent-yield for aromatic monomers is achieved over carbon nitride heterojunctions. • The photo-excited electron and hole synergistically trigger the C−C bond cleavage. • Carbon nitride heterojunctions accelerate electron-hole separation and migration. [ABSTRACT FROM AUTHOR]

Abstract: An individual's decision‐making behavior is heavily influenced by and adapted to external environmental factors. Given that software development is a human‐centered activity, individual decision‐making behavior may affect the software project quality. Although environmental factors affecting decision‐making behavior in software projects have been identified in prior literature, there is not yet an objective and a full taxonomy of these factors. Thus, it is not trivial to manage these complex and diverse factors. To address this deficiency, we first design a semantic similarity algorithm between words by utilizing the synonymy and hypernymy relationships in WordNet. Further, we propose a method to measure semantic similarity between phrases and apply it into k‐means clustering algorithm to group these factors. Subsequently, we obtain a taxonomy of the environmental factors affecting individual decision‐making behavior in software projects, which includes 11 broad categories, each containing 2 to 5 sub‐categories. The taxonomy presented herein is obtained by an objective method, and quite comprehensive, with appropriate references provided. The taxonomy holds significant value for researchers and practitioners; it can help them to better understand the major aspects of environmental factors, also to predict and guide the behavior of individuals during decision making towards a successful completion of software projects. [ABSTRACT FROM AUTHOR]

[Display omitted] • A nearly total conversion and > 98% selectivity of C-C bond cleavage is achieved. • Sufficient superoxide radicals are necessary for highly selective C-C bond cleavage under visible light. • Efficient photocatalytic C-C bonds breaking towards lignin β -O-4 model compounds. • Ru single atoms outperform the nanoparticles for photocatalytic C-C bond cleavage. • C β -H extraction by photogenerated hole is the critical step of the transformation. The selective cleavage of the C C bonds in lignin is highly pursued to obtain aromatic monomers from renewable resources but remains challenging due to their high dissociation energies and steric hindrance between bulky aromatic groups. Herein, a mesoporous carbon nitride-supported ruthenium single-atom photocatalyst (Ru 1 /MCN) is reported for efficient oxidative C α -C β bonds scissoring towards lignin β -O-4 model compounds with high activity and selectivity under visible–light irradiation and room temperature. With this strategy, a nearly total conversion of > 99% and > 98% selectivity of C C bond cleavage can be achieved upon 2–phenoxy–1–phenylethanol. In-depth investigations verify that the C β -H extraction by photogenerated holes is the critical step of the transformation, which directly generates the C β radical intermediates and thus promotes the selective C α -C β bonds breaking by coupling with superoxide radicals induced by photogenerated electrons. This work explores the potential of single-atom catalysts for photocatalytic production of aromatics from renewable biomass feedstocks. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation is an eco-friendly technology for volatile organic compound (VOC) removal, but searching for a highly efficient photocatalyst system remains a challenge. Here, a novel photocatalyst, ZnO/Ti 3 C 2 T X composite, was developed by the electrostatic deposition strategy, wherein Ti 3 C 2 T X nanosheets serve as a support to provide abundant surface-active sites for loading ZnO spheres and adsorbing VOC molecules. Furthermore, successive catalytic centers are formed to enlarge the photocatalytic reaction interface, thereby minimizing the photogenerated electron transfer distances. Moreover, a Schottky heterojunction was successfully formed between the ZnO spheres and Ti 3 C 2 T X nanosheets, which further suppressed the recombination of photogenerated electron–hole pairs. As a result, the ZnO/Ti 3 C 2 T X composite exhibited enhanced photocatalytic activity, universality and stability in VOCs degradation. The photodegradation efficiencies of formaldehyde, methyl alcohol and acetone were as high as 91 %, 84 % and 80 % by ZnO/Ti 3 C 2 T X composite, respectively. The pseudo-first-order kinetic constant of formaldehyde decomposition on ZnO/Ti 3 C 2 T X was 2.69 times greater than that on pristine ZnO. This work presents a novel photocatalyst system of ZnO/Ti 3 C 2 T X composite and provides an insight for the development of highly efficient photocatalysts for the degradation of VOCs. [Display omitted] • ZnO/Ti 3 C 2 T X composite with Schottky heterojunction was successfully synthesized. • Successive catalytic centers minimized the photogenerated e− transfer distances. • Enhanced adsorption performance and photocatalytic activity were achieved. • ZnO/Ti 3 C 2 T X exhibited universality and stability in VOCs photodegradation. [ABSTRACT FROM AUTHOR]

The inevitable problem of machining accuracy that follows accelerated tool wear deters severely the drilling of carbon fiber reinforced plastics/titanium (CFRP/Ti) stacks and is attributed to the cutting mechanism inherent to drilling and drill geometry. This paper develops orbital drilling of this stacked material by use of a special cutter under a dry machining condition and analyzes the characteristics of the variation in hole diameter and roundness. The influence of spindle speed for both CFRP and Ti alloy segments, and the bore and tool diameter ratio on these indexes with progressive tool wear is further studied. The experimental results show that the hole diameter at the CFRP exit always maintained the maximum value; spindle speed when machining different segments can improve or decrease these hole accuracy indexes, and the ratio of bore and tool diameter has greater influence on the roundness of the CFRP layer than that of the Ti alloy layer. [ABSTRACT FROM AUTHOR]

We report the preparation and hydrogenation performance of a single-site palladium catalyst that was obtained by the anchoring of Pd atoms into the cavities of mesoporous polymeric graphitic carbon nitride. The characterization of the material confirmed the atomic dispersion of the palladium phase throughout the sample. The catalyst was applied for three-phase hydrogenations of alkynes and nitroarenes in a continuous-flow reactor, showing its high activity and product selectivity in comparison with benchmark catalysts based on nanoparticles. Density functional theory calculations provided fundamental insights into the material structure and attributed the high catalyst activity and selectivity to the facile hydrogen activation and hydrocarbon adsorption on atomically dispersed Pd sites. [ABSTRACT FROM AUTHOR]

Wir beschreiben die Herstellung und das Hydrierungsverhalten eines Einzelatom ‐ Palladiumkatalysators, geschaffen durch die Verankerung von Pd ‐ Atomen in den Mesoporen eines graphitischen Kohlenstoffnitridpolymers. Die Analyse des Materials bestätigt die atomare Dispersion der Palladium ‐ Phase über die komplette Probe. Gegenüber nanopartikelbasierten Vergleichskatalysatoren zeigte sich die hohe Aktivität und Selektivität deutlich bei Anwendung in der kontinuierlichen Drei ‐ Phasen ‐ Hydrierung von Alkinen und Nitroarenen in einem Durchflussreaktor. Dichtefunktionalrechnungen ermöglichten die Erarbeitung fundamentaler Erkenntnisse betreffend Materialstruktur und erlaubten, die hohe katalytische Aktivität und Selektivität auf die einfache Wasserstoffaktivierung und Kohlenwasserstoffadsorption auf den atomar verteilten Pd ‐ Strukturen zurückzuführen. Ein (geschütztes) Atom genügt: Die einzigartige Porenstruktur von Kohlenstoffnitriden ermöglicht die stabile Einlagerung isolierter Palladiumatome. Dieser heterogene „Single ‐ site”︁ ‐ Katalysator für selektive Hydrierungen übertrifft die modifizierten Palladium ‐ Nanopartikel, welche den derzeitigen Stand der Technik darstellen. [ABSTRACT FROM AUTHOR]

Effectively harnessing renewable and inexhaustible solar radiation for energy conversion has attracted significant research interest in the past decade. Solar thermal conversion, as a ubiquitous phenomenon, can be implemented to evaporate water and concurrently boost photocatalytic performance for addressing freshwater scarcity and energy crisis. Most recently, solar water evaporation accompanied by photocatalytic degradation, sterilization, and hydrogen production has been proposed as a promising avenue to endow new vitality into the field of clean water and energy production. Driven by the advances of rationally designed solar-powered functional materials, a large variety of photothermal-coupled photocatalysis technologies have been exploited. In this context, it is imperative to summarize the recent progress and discuss the challenges in this multidisciplinary field. Herein, we overview photothermal materials based on various fundamental principles and highlight emerging applications in the areas of solar water evaporation, water purification, and solar-driven energy production. Furthermore, the challenges and perspectives toward both fundamental research and practical applications are also proposed. It is envisioned that this review can provide insightful suggestions to further advance the development of integrated solar thermal driven water evaporation and photocatalytic systems to fulfill concurrent energy conversion and environmental applications. [Display omitted] • The main design principles of concurrent photothermal and catalytic materials are summarized. • The photothermal energy boost physical and chemical reactions for improved water treatment. • The synergy of photothermal effect and photocatalysis can take full advantage of solar energy. • Sustainable water treatment with low-energy consumption shows great potentials in practical applications. [ABSTRACT FROM AUTHOR]