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Abstract Metallosalen covalent organic frameworks (M(salen)‐COFs) have garnered significant attention as promising candidates for advanced heterogeneous catalysis, including organocatalysis, electrocatalysis, and photocatalysis, due to their unique structural advantages (combining molecules catalysts and crystalline porous materials) and tunable topological network. It is essential to provide a comprehensive overview of emerging designs of M(salen)‐COFs and corresponding advances in this field. Herein, this review first summarizes the reported metallolinkers and the synthesis methods of M(salen)‐COFs. In addition, the review enumerates the excellent M(salen)‐COF based heterogeneous catalysts and discusses the fundamental mechanisms behind the outstanding heterogeneous catalytic performance of M(salen)‐COFs. These mechanisms include the pore enrichment effect (enhancing local concentration within porous materials to promote catalytic reactions), the three‐in‐one strategy (integrating enrichment, reduction, and oxidation sites in one system), and the incorporation of a built‐in electric field (implanting a built‐in electric field in heterometallic phthalocyanine covalent organic frameworks). Furthermore, this review discusses the challenges and prospects related to M(salen)‐COFs in heterogeneous catalysis.

Abstract This study has introduced a pioneering methodology by employing biochars as a basic carbocatalyst in the context of multicomponent reactions. Biochars were produced from different manures and organic wastes using the pyrolysis-carbonization process under limited oxygen conditions. The prepared biochars were well characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) analysis, and powder X-ray diffraction (XRD). The chemical characteristics and potentiometric titration analysis provide compelling evidence of the intriguing basicity properties exhibited by the prepared biochars. The pH values, ash content, and potentiometric titration results confirmed the exceptional basicity characteristics of cow manure biochar formed at 600 oC (CB600), establishing it as the most basic carbocatalyst in this study. Encouraged by these initial results, the activity of the biochars as basic carbocatalysts was evaluated in multicomponent synthesis of 4H-benzo[h]chromene and pyranopyrazoles and 600 °C exhibited the most pronounced catalytic performance owing to its superior total basicity. By these findings, it can be asserted that this work introduces the groundbreaking application of biochars as potent basic carbocatalysts for the multicomponent synthesis of structurally diverse heterocycles. Unveiling the vital basic role of biochars will definitely open up new opportunities in organic chemistry and provide salient features for environmentally-friendly chemistry, including easy retrieval, non-toxicity, and widespread accessibility. Graphical Abstract

More and more attention has been paid to strain-based regulation of catalytic activity. To guide regulation of catalytic performance via strain engineering, adsorption and reactions of AHx (A = C, N, O, x ≤ 3) were investigated on uniformly strained In2O3 (110), rutile TiO2 (110), and tetragonal ZrO2 (101) from −2% to 4%. The results show that adsorption energies vary linearly with strain; expansive strain enhances the adsorption of most adsorbates. Unlike the adsorbate scaling relations that are central atom dependent, the adsorbate scaling relations on strained surfaces are central atom independent. C–H/O–H bonds are elongated/shortened with expansive strain, and adsorption energies of CHx generally change more than those of OHx and NHx, which can be rationalized with effective medium theory and pertinent bond energies. Thermodynamically, In2O3(110)/ZrO2(101) is the most active/inactive. The estimated variation of rate constants at 300 K from 0% to 2% strain based on the Brønsted–Evans–Polanyi relationship demonstrates great strain regulation potential of catalytic performance on these oxide surfaces. Finally, it is demonstrated that strain tends to facilitate the reactions whose sum of the stoichiometric number is positive, which can be used as a rule to guide strain engineering for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

A metal-free, effective, and sustainable protocol has been developed to carry out C–N and C–C bond-forming reactions leading to the formation of 5-amino-pyrazole-4-carbonitriles and 1H-pyrazolo [1,2-b] phthalazine-5, 10-dione derivatives via a tandem multicomponent reaction using mesoporous MPC@TMG as a basic heterogeneous organocatalyst. The reactions were performed in aqueous medium at room temperature. The synthesized organocatalyst MPC@TMG was characterized by numerous spectroscopic techniques such as Fourier Transform Infrared (FTIR), Powder X-ray diffraction (PXRD), Brunauer-Emmett-Teller (BET), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), elemental mapping, and Thermal Gravimetric (TG) analyses. MPC@TMG displayed excellent catalytic potential, high thermochemical stability, and reusability for up to eight catalytic runs and offered the title compounds in excellent yields (>90 %) in a short reaction time (6–15 min). The synthesized compounds were characterized through FTIR, 1H, and 13C Nuclear Magnetic Resonance (NMR) spectroscopy. The use of water as a green solvent, the generality of the method, easy catalyst recovery, a simple work-up procedure, and zero involvement of any metal are the key features of the present protocol making it green and sustainable for the synthesis of the desired heterocycles and is supported by the calculations for green metrics parameters.

Modelling catalytic fixed bed reactors with a small tube-to-particle diameter ratio requires a detailed description of the interactions between fluid flow, intra-particle transport, and the chemical reaction(s) within the catalyst. Particle-resolved computational fluid dynamics (PRCFD) simulations are the most promising approach to predict the behaviour of these reactors accurately, since they take into account the local packed bed structure explicitly. In this work, a conjugated heat and mass transfer model for use in PRCFD simulations is presented in order to couple the fluid flow through the fixed bed with transport and reaction in the porous catalyst, while guaranteeing the no-slip boundary condition at the fluid–solid interface. For this purpose, the solutions of the solid and fluid domain are computed separately and are coupled by calculation and updating the boundary condition at the particle surface. Owing to the consideration of secondary gradients, the developed transfer model is also valid for unstructured calculation meshes containing non-orthogonal cells at the fluid–solid interface. Such meshes are often used to resolve complex geometries, such as a packed bed, in a computationally efficient manner. The coupling approach is validated using cases for which an analytical solution or literature correlations derived from experimental data are available. The simulation results of a short catalytic packed bed with rings catalysing the partial oxidation of n-butane to maleic anhydride exemplify the potential of PRCFD involving reactions to analyse the catalyst performance in great detail.

ABSTRACTSynthesis of fatty acid butyl esters using snail shells is attractive and increases the share of renewable resources because the snail shells are a waste of the food industry and 1-butanol can be obtained from renewable resources. Chemical and instrumental analysis methods (XRDA, FT-IR, EDS) were used for the evaluation of the chemical composition of snail shells. It was found that composition slightly depends on the kind and growing conditions, but in all the cases the main component in raw shells is CaCO3. After calcination for 5 h at a temperature of 850 °C, almost pure CaO (93.69 ± 0.43% %) is formed, which is used as a catalyst in the triglyceride transesterification process. SEM studies showed that the structure of the shells becomes porous after calcination, which increases the efficiency of the process. The Response surface methodology was used for the optimization of rapeseed oil transesterification with 1-butanol. It was found that the optimum transesterification conditions when the reaction temperature is 110°C are the following: 1-butanol-to-oil molar ratio of 10.6:1, a snail shell content of 7.53 wt%, and a reaction time of 10.77 h. Under these conditions, the 99.25 wt% yield of rapeseed butyl esters was obtained.

The production of 2,5-furandicarboxylic acid (FDCA) through green reaction routes is of crucial scientific value for the production of sustainable polymers. This study explores the active centers in cobalt-nitrogen-doped carbon (Co-N/C) for FDCA production. It was established that Co-Nx synergistically along with the nitrogen-doped carbon acted as centers for 5-hydroxymethylfurfural (HMF) oxidation. This study demonstrates a sustainable method for FDCA production from HMF without using precious metals, organic solvents, and harsh basic environments. Co-N/C catalyst displayed a high FDCA yield of ∼90% in an aqueous medium under mildly basic conditions in 34 h with 100% HMF conversion. An innovative strategy of stepwise base addition has been proposed to effectively accelerate the generation reaction of FDCA. The detrimental effects of high heating rate and calcination temperature on the active centers were also thoroughly investigated. Through DFT simulations it was established that Co-Nx aided in the activation of oxygen for HMF oxidation.

The local reaction environment of catalytic active sites can be manipulated to modify the kinetics and thermodynamic properties of heterogeneous catalysis. Because of the unique physical–chemical nature of water, heterogeneously catalyzed reactions involving specific interactions between water molecules and active sites on catalysts exhibit distinct outcomes that are different from those performed in the absence of water. Zeolitic materials are being applied with the presence of water for heterogeneous catalytic reactions in the chemical industry and our transition to sustainable energy. Mechanistic investigation and in-depth understanding about the behaviors and the roles of water are essentially required for zeolite chemistry and catalysis. In this review, we focus on the discussions of the nature and structures of water adsorbed/stabilized on Brønsted and Lewis acidic zeolites based on experimental observations as well as theoretical calculation results. The unveiled functions of water structures in determining the catalytic efficacy of zeolite-catalyzed reactions have been overviewed and the strategies frequently developed for enhancing the stabilization of zeolite catalysts are highlighted. Recent advancement will contribute to the development of innovative catalytic reactions and the rationalization of catalytic performances in terms of activity, selectivity and stability with the presence of water vapor or in condensed aqueous phase. [ABSTRACT FROM AUTHOR]

Activation of ubiquitous C(sp3)−H bonds is extremely attractive but remains a great challenge. Heterogeneous photocatalysis offers a promising and sustainable approach for C(sp3)−H activation and has been fast developing in the past decade. This Minireview focuses on mechanism and strategies for heterogeneous photocatalytic C(sp3)−H activation. After introducing mechanistic insights, heterogeneous photocatalytic strategies for C(sp3)−H activation including precise design of active sites, regulation of reactive radical species, improving charge separation and reactor innovations are discussed. In addition, recent advances in C(sp3)−H activation of hydrocarbons, alcohols, ethers, amines and amides by heterogeneous photocatalysis are summarized. Lastly, challenges and opportunities are outlined to encourage more efforts for the development of this exciting and promising field. [ABSTRACT FROM AUTHOR]

The adsorption of anions onto metal surfaces is important in many applications including effective (electro)catalyst design, metal surface modification, and contaminant removal in wastewater treatment. In electrocatalysis, anions can be both reactive intermediates or site‐blocking spectators, where their adsorption strength therefore dictates the rate of reaction. In this work, we have measured the adsorption energy of a series of carboxylic acids on a Pt (111) single‐crystal electrode surface from aqueous solution. We find that the adsorption strength of the carboxylate anion is linearly correlated with its acid‐dissociation constant (pKa) and therefore the heterolytic O−H bond dissociation strength in solution. Using density functional theory modeling, we split the anion adsorption energy into a sum of the adsorption energy and electron affinity of a neutral (carboxyl) radical. Surprisingly, the adsorption energy of the carboxyl radicals are similar and therefore the large difference in electron affinity is what dictates anion adsorption strength; the greater the cost in energy to remove the electron from the anion upon adsorption, the weaker its binding. Therefore, at least within a class of anions with similar structure and surface binding atoms, both electron affinity and acidity are predictive descriptors of adsorption strength. [ABSTRACT FROM AUTHOR]

The concept of "Frustrated Lewis pairs" (FLPs), which emerged from the discovery that H2 can be reversibly activated by combinations of sterically encumbered Lewis acids and bases. Since then, the field of FLP chemistry has expanded enormously. One of the most remarkable achievements is the development of FLP catalysts for hydrogenation, which are environmentally friendly and have potential industrial application prospects. In recent years, this unique catalysis concept has pushed the study of FLP chemistry to a new direction: heterogeneous FLP catalysts. This review outlines the recent research progress of new strategies to design and synthesize heterogeneous FLPs for hydrogenation reaction, and prospects the development of novel heterogeneous FLP catalysts. [ABSTRACT FROM AUTHOR]

Catalytic conversion of light alkanes (C1‐C3) to aromatics offers an attractive valorization route for abundant gas resources and has been a prevalent topic of research over the past few decades. Despite considerable advancements in the understanding of these reactions, several fundamental and practical hurdles have prevented their industrial application. Among the numerous attempts to resolve these issues, co‐feeding certain additives yields promising results, including the activation of alkanes under milder conditions, an increase in catalytic stability, and a shift in product distribution towards more desirable compounds. Systematic studies have elucidated the precise working mechanism of the co‐feeds in aromatization systems, explaining the experimentally observed results. This review provides an extensive compilation of information on the application of co‐feeds in light alkane aromatization, which has accumulated in the literature since the pioneering reports in the 1990s. Detailed summaries are provided for each additive, ranging from hydrocarbons to oxidants. Viable strategies for future work in this field, aiming to bridge the gap between academic studies and industrial applications, are also discussed. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) utilization as a carbonyl source is an attractive and promising approach to yielding value‐added organic urea derivatives, which are currently produced with toxic reagents such as phosgene and carbon monoxide, along with the contribution to mitigating global warming. However, the direct intermolecular reaction between CO2 and amines into organic urea derivatives has thermodynamic limitations, and such obstacles need to be considered well in order to establish efficient reaction systems. Herein, this review describes the thermodynamic aspects for producing several organic urea compounds, viz., N,N'‐dibutylurea, N,N'‐di(tert‐butyl)urea, 2‐imidazolidinone (ethylene urea), N,N'‐dimethyl‐2‐imidazolidinone, tetrahydro‐2‐pyrimidinone (propylene urea), and N,N'‐diphenylurea, based on the results of computational calculations. Besides, a variety of the state‐of‐the‐art reaction systems with/without catalyst for synthesizing such organic urea compounds operated under pressurized CO2 have been summarized and discussed to make not only advantages but also disadvantages clear. We have also overviewed the very recently reported approaches that employ alkylcarbamic acids as substrates and instead does not require external CO2. The thermodynamic and catalytic insights garnered here could be a fruitful guideline for fairly assessing each reaction system and further improving the efficiency of CO2 utilization as a carbonyl source. [ABSTRACT FROM AUTHOR]

Core‐shell Co3O4@CoO nanoparticles were prepared by calcination of rock‐salt CoO and fully characterized by PXRD, TEM and XPS measurements. XPS studies showed that the Co(III) cation concentration steadily increased and the OER activity of the resulting core‐shell Co3O4@CoO nanoparticles decreased with increasing calcination time, which was attributed to the increasing presence of catalytically inactive Co(III) cations. The decrease in OER activity was also observed for untreated CoO nanoparticles (1) after chronopotentiometric (CP) treatment at 10 mA cm−2 for 18 h. The IR and EEL spectra of the resulting nanoparticles are comparable to those of a fully oxidized Co3O4 sample (1–300), that was prepared by calcining of the CoO sample (1) for 1 h at 300 °C. [ABSTRACT FROM AUTHOR]

Multi‐enzyme reaction systems have become an interesting option to avoid transformation and purification steps in productive reactor‐based systems; when carried out in a single vessel, they are termed one‐pot systems. This novel work aims to model and simulate the behavior of a one‐pot heterogeneous catalysis system in a batch‐stirred bioreactor and in a continuous stirred bioreactor with co‐immobilized enzymes to determine the compromise operation temperature that maximizes the volumetric productivity, considering thermal decay of the biocatalyst. The production of fructose from lactose is considered a case study, using co‐immobilized β ${\beta }$ ‐galactosidase (β ${\beta }$ ‐gal) and glucose‐isomerase (GI) in a spherical particle. A diffusion and reaction mathematical model was used to calculate the effectiveness factor for every reaction species considering the thermal decay of both enzymes. Simulations in both batch and continuous operation were done at temperatures ranging from 40 to 60 °C, for initial enzyme activity load ratios ranging from 0.1 to 0.9 IUGI IUβ-gal-1 ${_{{\rm{{\rm \beta} }}{\kern 1pt} {\rm{ - gal}}{\kern 1pt} }^{ - 1} }$. Resulting effectiveness factors were close to one, indicating no significant limitations on reaction rates due to internal diffusional constraints. In both cases, temperature exerted a more substantial effect than the initial enzyme activity load ratio, showing different scenarios of high volumetric productivity (batch) or amount of produced fructose (continuous). [ABSTRACT FROM AUTHOR]

Phosphine‐functionalized metal‐organic frameworks (P‐MOFs) as an emerging class of coordination polymers, have provided novel opportunities for the development of heterogeneous catalysts. Yet, compared with the ubiquitous phosphine systems in homogeneous catalysis, heterogenization of phosphines in MOFs is still at its early stage. In this Minireview, we summarize the synthetic strategies, characterization and catalytic reactions based on the P‐MOFs reported in literature. In particular, various catalytic reactions are discussed in detail in terms of phosphine ligand structure‐function relationship, including the potential obstacles for future development. Finally, we discuss the possible solutions, including new types of reactions and techniques as the perspectives for the development of P‐MOF catalysts, highlighting the opportunities and challenges. [ABSTRACT FROM AUTHOR]

An efficient visible light-mediated and heterogeneous gold-catalyzed cross-coupling of aryldiazonium tetrafluoroborates and allyltrimethylsilane has been developed. The photosensitizer-free cross-coupling reaction proceeds smoothly in MeCN under irradiation with blue LEDs at room temperature by using 10 mol% of SBA-15-supported triphenylphosphine-gold(I) complex [SBA-15-Ph3PAuCl] as catalyst and provides a general and practical route for the synthesis of allylarenes in moderate to good yields. This heterogenized gold(I) catalyst can be readily recovered via a simple filtration of the reaction mixture and recycled up to eight times without any significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Herein, a hetero-structured catalyst CoP-Co supported on porous g-C 3 N 4 nanosheets (CoP-Co/CN-I) was prepared by pyrolysis and P-inducing strategy. The optimal catalyst achieves a turnover frequency (TOF) of 26 min−1 at room temperature and the apparent activation energy (E a) is 35.5 kJ·mol−1. The catalytic activity is ranked top among the non-precious metal phosphides or the other supports. Meanwhile, the catalytic activity has no significant decrease even after 5 cycles. The CoP/Co interfaces provide richly exposed active sites, optimize hydrogen/water absorption free energy via electronic coupling, and thus improve the catalytic activity. The experimental results reveal that the CoP/Co heterojunction improves the catalytic activity due to the construction of dual-active sites. This research facilitates the innovative construction of non-noble metal catalysts to meet industrial demand for heterogeneous catalysis. [Display omitted] • A CoP/Co heterojunction on porous g-C 3 N 4 nanosheets as a highly efficient catalyst is designed deliberately through pyrolysis and phosphorus-inducing (P-inducing) strategy. • The construction of Co-P and Co dual-active site in this research resulting in the ability to simultaneously active NH 3 BH 3 and H 2 O molecule on CoP-Co/CN-I and enhanced their intrinsic activity via tuning the surface electronic property. • An outstanding TOF of 26 min−1 was obtained over Co-P and Co dual-active sites on CoP-Co/CN-I compared with separate Co-P site or Co site during NH 3 BH 3 hydrolysis (Co activate H 2 O and Co-P activate NH 3 BH 3). Designing non-precious catalysts to synergistically achieve a facilitated exposure of abundant active sites is highly desired but remains a significant challenge. Herein, a hetero-structured catalyst CoP-Co supported on porous g-C 3 N 4 nanosheets (CoP-Co/CN-I) was prepared by pyrolysis and P-inducing strategy. The optimal catalyst achieves a turnover frequency (TOF) of 26 min−1 at room temperature and the apparent activation energy (E a) is 35.5 kJ·mol−1. The catalytic activity is ranked top among the non-precious metal phosphides or the other supports. Meanwhile, the catalytic activity has no significant decrease even after 5 cycles. The CoP/Co interfaces provide richly exposed active sites, optimize hydrogen/water absorption free energy via electronic coupling, and thus improve the catalytic activity. The experimental results reveal that the CoP/Co heterojunction improves the catalytic activity due to the construction of dual-active sites. This research facilitates the innovative construction of non-noble metal catalysts to meet industrial demand for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Composite silica materials have been developed by hydrothermal method and utilized as heterogeneous Hydrogen Bond Donor (HBD) catalysts, where the functionalized ketimine derivatives have been immobilized on the solid support. Such functional materials have been found to be efficient catalysts for the synthesis of cyclic carbonates through the installation of CO2 with epoxides. Characterization of these materials was systematically done using various spectroscopic and imaging techniques to confirm the presence of organic compounds on the silica surface. These composite materials exhibited significantly higher catalytic activity as compared to the other homogeneous methods. Additionally, this synthetic process was extremely convenient in terms of all the external parameters such as, solvent free condition at ambient reaction temperature with normal pressure of CO2, very low catalyst loading with proper regeneration and reusability of the catalyst. These facets have definitely made this technique greener and more sustainable. [ABSTRACT FROM AUTHOR]

Ruthenium (Ru) catalysts supported on cerium oxide (CeO2), which was composed of high crystallinity (HC) CeO2 covered by low crystallinity (LC) CeO2 were investigated. The ammonia synthesis activities of a series of Ru/CeO2(LC)/CeO2(HC), having different LC/HC ratios were evaluated, and various characterizations, such as N2 adsorption, X‐ray diffraction, hydrogen temperature‐programmed reduction (H2‐TPR), and hydrogen temperature‐programmed desorption (H2‐TPD), were performed. Ru/CeO2(LC)/CeO2(HC) (0.1) demonstrated higher activity. H2‐TPR revealed that H2 consumption increased as the LC/HC ratio increased. This indicates that the larger the amount of low crystallinity CeO2, the higher the reducibility. However, the results of H2‐TPD imply that the larger the amount of low crystallinity CeO2, the higher the interaction between adsorbed H2 and the catalyst surface. These results indicate that the balance of reducibility and hydrogen adsorption strength plays an important role in increasing the ammonia synthesis activity. [ABSTRACT FROM AUTHOR]

The catalytic activity and electrochemical promotion of catalysis (EPOC) of the bimetallic Pd−Co nanoparticles (10 nm) deposited on yttria‐stabilized zirconia were investigated for complete methane oxidation. The reaction was conducted under open‐circuit and under polarization in a temperature range of 320–400 °C in reducing, stoichiometric, and oxidizing conditions. The catalytic activity of the catalyst nanoparticles increased to 40 % upon positive polarization in all gaseous compositions. A comparison of three reaction conditions revealed that the highest reaction rate increase (enhancement ratio, ρ=1.4) occurs under reducing conditions. The reaction rate increased upon anodic polarization, resulting in non‐Faradaic electrochemical modification of catalytic activity (Λ≫1) in reducing and oxidizing conditions and Faradaic or electrochemical enhancement (Λ<1) in stoichiometric reaction condition. This work demonstrates that the formation of different Pd and Co oxide phases can be accurately controlled by electrochemical stimuli and, in reducing conditions, result in pseudo‐capacitor behaviour. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) with high porosity have garnered considerable interest for various applications owing to their robust and customizable structure. However, conventional COFs are hindered by their narrow pore size, which poses limitations for applications such as heterogeneous catalysis and guest delivery that typically involve large molecules. The development of hierarchically porous COF (HP‐COF), featuring a multi‐scale aperture distribution, offers a promising solution by significantly enhancing the diffusion capacity and mass transfer for larger molecules. This review focuses on the recent advances in the synthesis strategies of HP‐COF materials, including topological structure design, in‐situ templating, monolithic COF synthesis, defect engineering, and crystalline self‐transformation. The specific operational principles and affecting factors in the synthesis process are summarized and discussed, along with the applications of HP‐COFs in heterogeneous catalysis, toxic component treatment, optoelectronics, and the biomedical field. Overall, this review builds a bridge to understand HP‐COFs and provides guidance for further development of them on synthesis strategies and applications. [ABSTRACT FROM AUTHOR]

CO2 is a greenhouse gas that contributes to environmental deterioration; however, it can also be utilized as an abundant C1 resource for the production of valuable chemicals. Solar‐driven photoelectrocatalytic (PEC) CO2 utilization represents an advanced technology for the resourcing of CO2. The key to achieving PEC CO2 utilization lies in high‐performance semiconductor photoelectrodes. Si‐based photoelectrodes have attracted increasing attention in the field of PEC CO2 utilization due to their suitable band gap (1.1 eV), high carrier mobility, low cost, and abundance on Earth. There are two pathways to PEC CO2 utilization using Si‐based photoelectrodes: direct reduction of CO2 into small molecule fuels and chemicals, and fixation of CO2 with organic substrates to generate high‐value chemicals. The efficiency and product selectivity of PEC CO2 utilization depends on the structures of the photoelectrodes as well as the composition, morphology, and size of the catalysts. In recent years, significant and influential progress has been made in utilizing Si‐based photoelectrodes for PEC CO2 utilization. This review summarizes the latest research achievements in Si‐based PEC CO2 utilization, with a particular emphasis on the mechanistic understanding of CO2 reduction and fixation, which will inspire future developments in this field. [ABSTRACT FROM AUTHOR]

Amines are pivotal building blocks for a range of applications, including pharmaceuticals, polymers, agrochemicals, and organic synthesis. The hydrogenation of amides using molecular hydrogen via heterogeneous catalysis is considered a promising method for producing amines with considerably high atom efficiency, environmental friendliness, and eonomic viability. Continued developments have occurred in this area, with milestones reached in the hydrogenation of various amides to amines via heterogeneous catalysis. At present, no systematic analysis of the influence of amide structures on their reactivity and the required type of catalyst has been reported. This review describes the most recent advances in catalytic amide hydrogenation, paying special attention to the influence of structural features (cyclic amides and aliphatic acyclic amides) on catalyst performance. Structural features endow amides with specific reactivities, reflected in considerable differences in the ease of hydrogenation and diverse product selectivity. In addition, insights into the conversion of polyamides, fatty acids, and triglycerides to amines are provided. This review provides new perspectives for designing and applying heterogeneous catalysts adapted to specific conditions and amide structures. [ABSTRACT FROM AUTHOR]

The mesoporous carbons with abundant Fe–Co sites were prepared through one-step carbonization of a MOF materials (ZIF-67) with sodium iron ethylenediaminetetraacetic acid [NaFe(III)EDTA], which can facilitate the nucleation and growth of highly dispersed palladium active sites. The robust synergistic interaction between Pd and FeCo metal with moderate work functions is responsible for the enhanced catalytic activity. Interfacing Pd nano-particles with FeCo sites has been demonstrated for the first time to boost the heterogeneous catalysis of hydrogen production from formic acid, affording the high turnover frequency (TOF) value of 1288 h−1 at 303 K. The Pd–Fe–Co sites also help to achieve outstanding catalysis performance of in situ hydrogenating phenol. The 91.1 % of the conversion of phenol and 92.7 % of the selectivity of cyclohexanone has been obtained with formic acid as H-donor. [Display omitted] • FA dehydrogenation catalyst is applied in the in-situ hydrogenation of phenol. • PdFeCo alloy sites shows excellent activity with 92.7 % selectivity of cyclohexanone. • The catalyst shows a TOF value of 1288 h−1 at 303 K in FA dehydrogenation. • The PdFeCo alloy structure leads to the higher bifunctional catalytic activity. • The electron transfer within PdFeCo alloy was proved by various characterizations. [ABSTRACT FROM AUTHOR]

In this work, cadmium oxide (CdO) nanostructures were fabricated in good yields by calcining three different cadmium-based coordination polymer (CP) precursors, with a change in the alkyl group (methyl, ethyl, and tert-butyl) on the tridentate capping ligand, at 600 °C. The precursor-independent spherical morphology was observed in all the cases. On the other hand, a temperature-dependent hierarchical evolution of morphology from spherical (at 600 °C) to octahedron (at 700 °C) to icosahedron (at 800 °C) was observed for each of the precursors, as investigated by field-emission scanning electron microscopy. This hierarchical change in morphology has further been confirmed by the transmission electron microscopy (TEM) analysis. For all three CPs, the increase in the particle size of the nanostructures was correlated to an increase in the calcination temperature. With the help of Raman spectroscopy, the vibrational modes in these nanostructures were depicted, where the transversal and optical phonon modes and second-order optical modes displayed peaks at 270 and 950 cm–1, respectively. The energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy (XPS) were utilized for determining the elemental composition of the nanostructuresthe presence of Cd and O onlyevidencing their purity. The XPS analysis has also confirmed the Cd2+ and O2– oxidation states with the appearance of peaks in the ranges of 403–411 eV and 520–532 eV, respectively. Furthermore, the powder X-ray diffraction revealed the cubic phase of all the nanostructures. This was reaffirmed by the high-resolution transmission electron microscopy. Their characteristic absorption features were examined by the solid-state UV–vis diffuse reflectance spectroscopy, which showed a shoulder peak between 490 and 550 nm, and the resultant Tauc plots provided the band gap values in the range of 1.74–2 eV. A relationship of band gap values with particle sizes was established to justify the presence of the quantum confinement effect. Exploring their acid–base bifunctional nature, the spherical nanostructure (obtained at 600 °C) with the highest band gap value emerges as an extremely efficient, and recyclable heterogeneous catalyst for making coumarin-3-carboxylic acids (100% conversion) from the one-pot Knoevenagel-intramolecular cyclization tandem reaction of substituted salicylaldehydes and Meldrum's acid in just 1 h at ambient conditions in methanol. The detailed reaction mechanism has been discussed with the help of theoretical calculations and experimental evidence. [ABSTRACT FROM AUTHOR]

The chemically catalyzed production of fructose syrup from high concentrations of glucose is crucial for the food industry and biorefining. In this work, a single crystal catalyst was synthesized via protective desilication of zeolite while incorporating indium. Glucose was isomerized in methanol at concentrations as high as 33 wt % before being hydrolyzed with water. The final fructose production was 54.9 %, with 89.1 % selectivity and 93.3 % sugar recovery, the highest isomerization rate at the highest concentration ever reported. Indium was present in the single‐crystal catalyst as oxide nanoparticles and boundary framework atoms, and it achieved intelligent cooperation in the production of fructose syrup in methanol by catalyzing isomerization and selective glycosidation, minimizing degradation due to fructose accumulation and eliminating side reactions. This study contributed to the advancement of the industrial practice of chemically catalyzed glucose isomerization. [ABSTRACT FROM AUTHOR]

Carbon‐based single‐atom catalysts (SACs) have attracted tremendous interest in heterogeneous catalysis. However, the common electric heating techniques to produce carbon‐based SACs usually suffer from prolonged heating time and tedious operations. Herein, a general and facile microwave‐assisted rapid pyrolysis method is developed to afford carbon‐based SACs within 3 min without inert gas protection. The obtained carbon‐based SACs present high porosity and comparable carbonization degree to those obtained by electric heating techniques. Specifically, the single‐atom Ni implanted N‐doped carbon (Ni1−N−C) derived from a Ni‐doped metal–organic framework (Ni‐ZIF‐8) exhibits remarkable CO Faradaic efficiency (96 %) with a substantial CO partial current density (jCO) up to 1.06 A/cm2 in CO2 electroreduction, far superior to the counterpart obtained by traditional pyrolysis with electric heating. Mechanism investigations reveal that the resulting Ni1−N−C presents abundant defective sites and mesoporous structure, greatly facilitating CO2 adsorption and mass transfer. This work establishes a versatile approach to rapid and large‐scale synthesis of SACs as well as other carbon‐based materials for efficient catalysis. [ABSTRACT FROM AUTHOR]

Carbon nitride (CN) materials have been employed as catalysts in many scientific fields. Moreover, highly crystalline CN as an ideal model material for key problems in catalytic reaction research has received a lot of attention. Herein, the Li+ incorporated highly crystalline poly(triazine imide) (PTI–Li+) with a well‐defined structure is successfully fabricated through the ionothermal method. The atomically dispersed Li in the PTI–Li+ serve as the active sites in the selective catalytic oxidation of H2S, and the interaction between Li ions and PTI–Li+ framework extends electron delocalization and modulate electronic band structure resulting in improved O2 and H2S adsorption and activation ability. Consequently, PTI–Li+ shows excellent selective catalytic desulfurization activity and durability. This work not only designs an efficient desulfurization catalyst but also demonstrates the role of these atomically dispersed Li ions in PTI–Li+ during the catalytic reaction, enlightening the deeper understanding and wider application of carbon nitride materials. [ABSTRACT FROM AUTHOR]