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The catalytic hydrogenation of biomass-derived chemicals is essential in chemical industry due to the growing demand for sustainable and renewable energy sources. In this study, we present a comprehensive theoretical investigation regarding the hydrogenation of glycolaldehyde to ethylene glycol over a Ru/C catalyst by employing density functional theory and ab initio molecular dynamics simulations. With inclusion of explicit solvation, we have demonstrated that the glycolaldehyde hydrogenation is significantly improved due to the fast proton transfer through the hydrogen bond network. The enhanced activity could be attributed to the participation of the solvent water as the hydrogen source and the highly positively charged state of a Ru cluster in an aqueous phase, which are critical for the activation of aldehyde groups and proton-assisted hydrogenation. Overall, our findings provide valuable insights into glycolaldehyde hydrogenation over Ru/C catalysts in the aqueous phase, highlighting the importance of solvation effects in the biomass conversion. [ABSTRACT FROM AUTHOR]

Highly Dispersed Pd Nanoparticles Supported by Magnetically Separable Fe 3 O 4 @SiO 2 Nanotube for Catalytic Hydrogenation of Nitroaromatics. [Display omitted] • Highly dispersed Pd nanoparticles are prepared by in situ reduction on the amino group modified Fe 3 O 4 @SiO 2 nannotube. • Easily separated by external magnetic field and well-redispersed in solvent. • The conversion and selectivity both remain at a remarkable 98% after 6 cycles of the reaction. Selective hydrogenation of nitroaromatics is a crucial industrial reaction, but there are still challenges in developing nanocatalysts with stable active centers, yet easily recyclable characteristics. Here, a magnetically separable Pd/Fe 3 O 4 @SiO 2 nanocatalyst was prepared through the seeding growth of silica on the Fe 3 O 4 nanocrystal cluster (NC) followed by in situ reduction of Pd nanoparticles (NPs) on the amino group modified Fe 3 O 4 @SiO 2 nannotube (NT). The nanocatalyst showed good activity and stability in the hydrogenation of a series of nitroaromatics as the Pd NPs were highly dispersed on the nanotubes. Meanwhile, it could be easily separated from the reaction solution and well-redispersed in the solvent for the next-round reaction due to the superparamagnetic property of the Fe 3 O 4 NC and the good dispersibility of silica in many organic solvents. The magnetically separable nanocatalyst combined the high activity of the nanocatalyst and the convenient separation of a traditional heterogeneous catalyst, which effectively promote the practical application of nanomaterials in catalysis. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Transition metal‐catalyzed asymmetric hydrogenation is an efficient and direct synthetic method to access chiral compounds, which features simplicity, easy working‐up process, and high atomic economy. It typically relies on precious transition metal catalytic systems, including ruthenium, rhodium, iridium and palladium, which always face the difficulties of limited resources, high cost, and environmental contamination. Therefore, great efforts were made to apply earth‐abundant, low (non‐)toxic, and environmentally friendly transition metals, such as iron, cobalt, nickel and copper, to the asymmetric hydrogenation in the past decades, and some considerable breakthroughs have been obtained. In this review, we mainly summarized some recent research progress of nickel‐catalyzed asymmetric hydrogenation of prochiral unsaturated molecules, including olefins, imines and ketones. And continuous development of chiral nickel catalytic systems and the application of them into challenging asymmetric hydrogenation is prospected in the future. Key Scientists: Transition metal‐catalyzed asymmetric hydrogenation has been regarded as an important and direct approach to access chiral molecules. The first example of homogeneous catalytic asymmetric hydrogenation was developed by Knowles and Horner in 1968, respectively. In 1971, Kagan developed privileged chiral DIOP ligand for asymmetric hydrogenation. Halpern and Brown made deep studies on the Rh‐catalyzed asymmetric hydrogenation in 1977, respectively. Noyori developed a powerful and privileged chiral BINAP ligand in 1980. Owing to Knowles and Noyori's great contribution in the field of catalytic asymmetric hydrogenation, they were awarded the Nobel Prize in Chemistry in 2001. In 1984, Ohkubo developed pioneering earth‐abundant transition metal Ni‐catalyzed asymmetric hydrogenation of ethyl α‐methylcrotonate. A great many scientists made tremendous contribution to the development of chiral privileged ligands, such as, Bosnich, Kumada, Giongo, Takaya, Miyashima, Achiwa, Burk, Pflaltz, Chan, X. Zhang, Imamoto, Zhou, Genet, Sannicolo, Ding, Hoge, W. Zhang, Z. Zhang, Tang, these ligands owned wide application in the catalytic asymmetric hydrogenation. In addition, Zhou, Fan made deep investigation on the asymmetric hydrogenation of challenging aromatic heterocyclic compounds. Owing to the great importance of the development of the asymmetric (transfer) hydrogenation promoted by cheap transition metal catalytic systems, some researchers, such as Hamada, Gao, J. S. Zhou, Chirik, X. Zhang, Y.‐G. Zhou, W. Zhang, Lv, Dong, Fu, Deng, and Hou, made great efforts to the development of earth‐abundant nickel‐catalyzed asymmetric hydrogenation of prochiral unsaturated molecules, including olefins, imines and ketones. In addition, there are some other scientists that have also made great contribution to the development of catalytic asymmetric hydrogenation and Ni‐catalyzed asymmetric transformation, with too limited space to list all of them. [ABSTRACT FROM AUTHOR]

To develop efficient catalysts for CO2 hydrogenation to dimethyl ether, Cu–Al2O3–TiO2–Ti3C2/HZSM-5 bifunctional catalysts were prepared by the surfactant PVP-assisted coprecipitation. The influence of Ti3C2 on Cu–Al2O3-based catalysts was investigated. The characterization results revealed that slight oxidation of the Ti3C2 surface generated highly dispersed TiO2 nanoparticles that the doping of TiO2‒Ti3C2 in the Cu‒Al2O3 catalyst increased the specific surface area of the catalyst and promoted the formation and growth of Cu nanoparticles, and that strong interactions occurred between TiO2‒Ti3C2 and the Cu components. The number of oxygen vacancies at the interface between TiO2‒Ti3C2 and Cu increased by 17%, and the electronic kinetic energy of Cu0 decreased by 0.1 eV, with the electron-rich oxygen vacancies transferring electrons to Cu2+ ions and maintaining more Cu species in lower oxidation states. Reactions were carried out at 260 °C and 3.0 MPa with a gaseous hourly space velocity (GHSV) of 1500 cm3‧g−1‧h−1 using Cu–Al2O3–TiO2–Ti3C2/HZSM-5 with 5.0 wt% Ti3C2 as the hydrogenation catalyst, which provided a CO2 conversion of 26.8% with 57.8% selectivity for DME. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Transition metal‐catalyzed asymmetric hydrogenation is an efficient and direct synthetic method to access chiral compounds, which features simplicity, easy working‐up process, and high atomic economy. It typically relies on precious transition metal catalytic systems, including ruthenium, rhodium, iridium and palladium, which always face the difficulties of limited resources, high cost, and environmental contamination. Therefore, great efforts were made to apply earth‐abundant, low (non‐)toxic, and environmentally friendly transition metals, such as iron, cobalt, nickel and copper, to the asymmetric hydrogenation in the past decades, and some considerable breakthroughs have been obtained. In this review, we mainly summarized some recent research progress of nickel‐catalyzed asymmetric hydrogenation of prochiral unsaturated molecules, including olefins, imines and ketones. And continuous development of chiral nickel catalytic systems and the application of them into challenging asymmetric hydrogenation is prospected in the future. Key Scientists: Transition metal‐catalyzed asymmetric hydrogenation has been regarded as an important and direct approach to access chiral molecules. The first example of homogeneous catalytic asymmetric hydrogenation was developed by Knowles and Horner in 1968, respectively. In 1971, Kagan developed privileged chiral DIOP ligand for asymmetric hydrogenation. Halpern and Brown made deep studies on the Rh‐catalyzed asymmetric hydrogenation in 1977, respectively. Noyori developed a powerful and privileged chiral BINAP ligand in 1980. Owing to Knowles and Noyori's great contribution in the field of catalytic asymmetric hydrogenation, they were awarded the Nobel Prize in Chemistry in 2001. In 1984, Ohkubo developed pioneering earth‐abundant transition metal Ni‐catalyzed asymmetric hydrogenation of ethyl α‐methylcrotonate. A great many scientists made tremendous contribution to the development of chiral privileged ligands, such as, Bosnich, Kumada, Giongo, Takaya, Miyashima, Achiwa, Burk, Pflaltz, Chan, X. Zhang, Imamoto, Zhou, Genet, Sannicolo, Ding, Hoge, W. Zhang, Z. Zhang, Tang, these ligands owned wide application in the catalytic asymmetric hydrogenation. In addition, Zhou, Fan made deep investigation on the asymmetric hydrogenation of challenging aromatic heterocyclic compounds. Owing to the great importance of the development of the asymmetric (transfer) hydrogenation promoted by cheap transition metal catalytic systems, some researchers, such as Hamada, Gao, J. S. Zhou, Chirik, X. Zhang, Y.‐G. Zhou, W. Zhang, Lv, Dong, Fu, Deng, and Hou, made great efforts to the development of earth‐abundant nickel‐catalyzed asymmetric hydrogenation of prochiral unsaturated molecules, including olefins, imines and ketones. In addition, there are some other scientists that have also made great contribution to the development of catalytic asymmetric hydrogenation and Ni‐catalyzed asymmetric transformation, with too limited space to list all of them. [ABSTRACT FROM AUTHOR]

The catalytic hydrogenation of quinoline to decahydroquinoline (DHQ) formation is studied for various parameters such as temperature, hydrogen pressure, reaction time, solvents, reactant-to-solvent ratio, and catalyst loading over 5%Pd loaded on alumina (Pd/Al 2 O 3) to obtain optimal reaction conditions. The hydrogen uptake of quinoline in the liquid phase reaction using isopropylalcohol (IPA) is studied in an autoclave reactor. The optimum reaction parameters of 50 bar H 2 pressure and 175oC with reactant to solvent ratio of 1:9 for reaction time of 5 h are observed. The effect of IPA solvent showed that hydrogen uptake of 6.91 wt% with complete hydrogenation of quinoline and DHQ yield of more than 99% is observed. The reaction kinetic model is developed for a simplified reaction mechanism and is simulated using the Markov Chain Monte Carlo (MCMC) simulation tool to predict the rate constants and the experimental observations are validated with the model predictions. The activation energy for quinoline hydrogenation to py-THQ formation is estimated to be 136.57 kJ/mol. It is envisaged that quinoline hydrogenation to pz-THQ is the rate-limiting step in the DHQ formation. [Display omitted] • Liquid organic hydrogen carrier (LOHC) as a sustainable energy storage solution. • Complete catalytic hydrogenation of quinoline to decahydroquinoline (DHQ). • A simpified reaction mechanism proposed for quinoline to DHQ formation. • Quinoline hydrogen uptake of 6.91 wt % is obtained using IPA solvent. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid porous materials (OIHMs) inherit the unique properties from both organic and inorganic components, and the flexibility in the incorporation of functional groups renders the OIHMs an ideal platform for the construction of catalytic materials with multiple active sites. The preparation of OIHMs with precise locations of organic–inorganic components and tunable structures is one of the important topics for the catalytic application of OIHMs, but it is still very challenging. In this feature article, we describe our work related to the preparation of OIHMs via confining active sites in the nanostructure and a layer-by-layer assembly method and their applications in acid–base catalysis, catalytic hydrogenation and photocatalysis with a focus on the elucidation of the synergistic effects of different active sites and the unique properties of OIHMs in catalysis. [ABSTRACT FROM AUTHOR]

Solar-driven CO 2 hydrogenation reactions are an attractive approach for the production of chemicals in the CO 2 utilization. We emphasize the importance of reliable temperature measurements for assessing catalyst performance and report the effect of uneven temperature distribution on the product selectivity of the CO 2 hydrogenation reaction of Ru/TiO 2 catalysts, as well as the CO 2 hydrogenation reaction of Ru/TiO 2 catalysts in dark and under UV, visible IR, and full-spectrum light conditions. Full-spectrum utilization exhibits higher activity at the same temperature. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations clarify the reaction pathway of CO 2 hydrogenation to methane, revealing that UV and visible infrared light promote the adsorption and activation processes at different stages along the chemical reaction pathway, respectively. These findings can facilitate additional innovative ideas for the mechanism study and future development of next-generation photothermal catalysts based on full-spectrum utilization. • Uncovering the misclassification of product selectivity due to heterogeneous temperature distribution on the catalyst. • Revealing the mechanism of action of different spectral light on the CO 2 hydrogenation reaction on Ru/TiO 2 catalysts. • This work provides a rigorous means of measuring catalyst temperature. [ABSTRACT FROM AUTHOR]

We report an HN-ZIF-67 catalyst with a large hollow structure and well-dispersed active sites by a facile diffusion-controlled strategy. Compared with the pristine ZIF-67 and semi-sealed ZIF-67, HN-ZIF-67 shows remarkable catalytic activity in the hydrogenation of nitro-compounds due to its highly dispersed active sites that are exposed to the substrate, and long cycle life. [ABSTRACT FROM AUTHOR]

The catalytic performance of liquid‐phase hydrogenation of 1,4‐butynediol (BYD) to 1,4‐butanediol (BDO) was studied on silica‐supported Ni catalysts prepared by impregnation, sol‐gel, and ammonia evaporation methods, respectively. Due to the formation of nickel phyllosilicate, the Ni species in Ni/SiO2‐AE catalyst prepared by ammonia evaporation is difficult to reduce at 450 °C, resulting in fewer Ni0 active sites and poor hydrogenation activity. As for the impregnated Ni/SiO2‐IM, its nickel particles are prone to aggregate seriously due to their weak interaction with the support which may be not conducive to catalytic hydrogenation. On the contrary, the Ni species introduced by sol‐gel method can homogenously embedded in the amorphous silica intersecting network structure with high metal dispersion and well physical confinement effect, which greatly promotes its BYD hydrogenation performance to obtain BDO with super high selectivity. [ABSTRACT FROM AUTHOR]

A series of Mn(I), Fe(II), and Co(II) complexes with PNH ligands bearing secondary amine functionality were prepared and tested in the catalytic transfer hydrogenation of nitriles using ammonia borane as a hydrogen source. Among all tested complexes, a tetracoordinate Fe(II) bromide, (PNH)FeBr2, proved the most effective, representing a rare example of a highly active iron-based catalytic system for transfer hydrogenation reactions beyond carbonyl compounds and the first example of the iron catalyst for the transfer hydrogenation of nitriles to the corresponding primary amines. Mechanistic studies point out a metal–ligand cooperative mechanism enabled by the secondary amine moiety of the PNH ligand. [ABSTRACT FROM AUTHOR]

ABSTRACT Among the problems encountered in the catalytic transfer hydrogenation reactions of ketones, the base sensitivity of ketones and the corrosive effects of the bases used in the reaction have an important place especially in industrial terms. Although there are various approaches to overcome this problem, solutions based on the intrinsic properties of the catalyst used seem more suitable. Within the scope of this study, a novel heterogeneous catalyst was prepared for the transfer hydrogenation reaction of ketones, which can operate in base‐free environment. To prepare the heterogeneous catalyst, 1,2‐diphenylethane‐1,2‐diamine was first tosylated and then the silyl derivative was synthesized and grafted onto mesoporous silica SBA‐15. Characterizations of the obtained heterogeneous catalyst and SBA‐15 were carried out by X‐ray diffractometer (XRD), N2 sorption, thermogravimetric analysis (TGA), scanning electron microscope (SEM), energy dispersive X‐ray analysis, and Fourier transform infrared (FT‐IR) analysis. The results obtained showed that the functionalized 1,2‐diphenylethane‐1,2‐diamine compound was successfully immobilized into the SBA‐15 structure. Determination of the catalytic activity of the heterogeneous catalyst was carried out in transfer hydrogenation reactions of various aromatic ketones. After determining the optimum reaction conditions with acetophenone, a conversion rate of (70%) was observed in the acetophenone to 1‐phenylethanol reaction that took place without a base. Under same conditions a higher conversion rate of (73%) was observed in the 4′‐chloroacetophenone to 1‐(4‐chlorophenyl)ethanol reaction. In the reactions performed to determine recyclability, after a 70% conversion rate, 61% and 65% conversion rates, respectively, were observed in the reaction from acetophenone to 1‐phenylethanol under the same conditions. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenation is one of the most important transformations in both academia and industry. Compared with direct hydrogenation with molecular hydrogen or transfer hydrogenations with hydrides, electrohydrogenation provides an alternative and practical pathway using proton as the hydrogen source. In this review, we have summarized the recent advances in electrohydrogenations of polar and non‐polar unsaturated compounds catalyzed by earth‐aubundant metal complexes. In addition, we also present a detailed discussion of the scope and limitations, plausible mechanisms and the opportunities for further development. [ABSTRACT FROM AUTHOR]

A new and efficient manufacturing technology is disclosed in the present work for the preparation of benzoylphenylureas and their key intermediates. This new route significantly reduces the number of reaction steps from six to three, resulting in a streamlined process. Additionally, the overall yield is increased from 56% to over 69%. Compared to the original process route, the new manufacturing route has the advantages of fewer chemical steps, higher overall yield, less process safety hazard and environmental impact. Considering these factors, the new manufacturing route exhibits considerable potential for industrialization. [ABSTRACT FROM AUTHOR]

The modification of petroleum resin (PR) by catalytic hydrogenation is an upgrading technology for producing high-value-added hydrogenated petroleum resin (HPR) from of pyrolysis petroleum by-product. This research employed alumina supports with different pore size distributions to prepare supported Mo-Ni type catalysts and investigated their catalytic hydrogenation performance on C9 petroleum resin. Catalysts prepared with bimodal pore alumina (BPA) supports effectively overcome the limitations of internal diffusion and increase the quantity of active sites, thus increasing the catalytic activity for hydrogenation. The experimental results demonstrated that MoNi/BPA achieved a hydrogenation degree of 99.94% for HC9PR, with the hydrogenated product having a Pt–Co colour of 2.37 Hazen. After 140 h of reaction, the hydrogenation degree of HC9PR remained at 96.51%, and the Pt–Co colour value was lower than 40 Hazen. This investigation confirms that solving the mass transfer issues of petroleum resin molecules in the pores of supported catalysts is key to designing efficient hydrogenation catalysts for petroleum resin. [ABSTRACT FROM AUTHOR]

Furfural hydrogenation is one of the most important reactions for the transformation of biomass‐derived resources into high value‐added chemicals. To achieve a highly efficient catalytic activity of the reaction, catalysts with a high dispersion of metal nanoparticles (NPs) on solid supports are required. However, the development of highly efficient and stable catalysts is still challenging. Herein, the highly dispersed nickel nanoparticles (Ni NPs) supported on the hierarchical ZSM‐5 nanosheets (Z5‐NS) derived from the hierarchical ZSM‐5 nanosheets@NiAl‐layered double hydroxides (LDHs) composites were successfully fabricated. Remarkably, the fabricated Z5‐NS/Ni catalyst exhibited a high furfural conversion of 85 % with a yield of furfuryl alcohol of 60 %. This work illustrates the fabrication of highly metal dispersed on solid supports with high metal loading, which can enhance the catalytic performances in the hydrogenation of biomass‐derived compounds. [ABSTRACT FROM AUTHOR]

The rotating packed bed (RPB) is suitable for catalytic hydrogenation of aromatic nitrocompounds whose reaction rate is limited by the mass transfer rate. However, the matching mechanism between the mass transfer rate and intrinsic reaction rate in the RPB reactor is still unclear. In this work, the matching relationship in the RPB reactor is studied by combining the characteristics of mass transfer and reaction in detail. Effects of various operating conditions on the gas–liquid mass transfer coefficient up to 0.31/s, under working conditions were studied and the mass transfer correlation was proposed. The hydrogenation of p‐nitroanisole was used as a probe reaction to analyze the matching mechanism. Various aromatic nitrocompounds in the RPB and stirred tank reactors were investigated. The reaction efficiency of the former is 5–20 times that of the latter, which further explained the universality of the matching mechanism in the RPB reactor. [ABSTRACT FROM AUTHOR]

We present a series of borane‐tethered cyclic (alkyl)(amino)carbene (cAAC)‐copper complexes, including a borane‐capped Cu(I) hydride. This hydride is unusually hydridic and reacts rapidly with both CO2 and 2,6‐dimethylphenol at room temperature. Its reactivity is distinct from variants without a tethered borane, and the underlying principles governing the enhanced hydricity were evaluated experimentally and theoretically. These stoichiometric results were extended to catalytic CO2 hydrogenation, and the borane‐tethered (intramolecular) system exhibits ~3‐fold enhancement relative to an intermolecular system. [ABSTRACT FROM AUTHOR]

The selective hydrogenation of biomass derivatives presents a promising pathway for the production of high‐value chemicals and fuels, thereby reducing reliance on traditional petrochemical industries. Recent strides in catalyst nanostructure engineering, achieved through tailored support properties, have significantly enhanced the hydrogenation performance in biomass upgrading. A comprehensive understanding of biomass selective upgrading reactions and the current advancement in supported catalysts is crucial for guiding future processes in renewable biomass. This review aims to summarize the development of supported nanocatalysts for the selective hydrogenation of the US DOE′s biomass platform compounds derivatives into valuable upgraded molecules. The discussion includes an exploration of the reaction mechanisms and conditions in catalytic transfer hydrogenation (CTH) and high‐pressure hydrogenation. By thoroughly examining the tailoring of supports, such as metal oxide catalysts and porous materials, in nano‐supported catalysts, we elucidate the promoting role of nanostructure engineering in biomass hydrogenation. This endeavor seeks to establish a robust theoretical foundation for the fabrication of highly efficient catalysts. Furthermore, the review proposes prospects in the field of biomass utilization and address application bottlenecks and industrial challenges associated with the large‐scale utilization of biomass. [ABSTRACT FROM AUTHOR]

Yearly, thousands of tons of wasted coffee grounds are produced according to high coffee consumption. Still, after the coffee brewing, wasted coffee grounds contain some amounts of caffeine (CAF). CAF, in turn, contains multiple O and N chelating atoms in its structure. These have a potential to be reductors for complexes of metals. In this context, within the present study, a set of CAF extracts derived from coffee beans and coffee grounds were obtained and then used for the one-step reduction of ReO4− ions with no additional toxic chemicals. Within this approach, CAF was applied as a secondary, green resource for the synthesis of unique rhenium nanoparticles (ReNPs) containing Re species at 0 and +6 oxidation states. The obtained ReNPs were identified and characterized with the use of X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Further, the capping and stabilization of ReNPs by CAF were verified with the aid of Fourier transformation infrared spectroscopy (FT-IR). The so-obtained "green" ReNPs were then used as a homogenous catalyst in the catalytic hydrogenation of 4-nitrophenol (4-NP). This new nanomaterial revealed a superior catalytic activity, leading to the complete reduction of 4-NP to 4-aminophenol within 40–60 min with a first-order rate constant of 0.255 min−1. [ABSTRACT FROM AUTHOR]

ABSTRACT The syntheses and bioevaluation of 3‐acyl‐2‐pyridones have garnered significant interest in recent years as a novel class of compounds with diverse biological activities. The bioactivities cover a wide range of therapeutic areas including antimicrobial, antitumor, anti‐inflammatory, antifungal, antibiotic, neuritogenic, cytotoxic, and antiviral activities. Therefore, 3‐acyl‐2‐pyridone scaffold offers a versatile platform for the development of new molecules with potential applications in medicinal chemistry. The recent exploration on synthesis and bioevaluation of 3‐acyl‐2‐pyridones has yielded promising results, making them attractive targets for further optimization and development of new therapeutic agents. This review summarizes the available information on total synthesis of 3‐acyl‐2‐pyridone containing natural products, and the other synthetic strategies developed for accessing the 3‐acyl pyridones such as multicomponent synthesis, condensation reaction, microwave‐assisted synthesis, catalytic hydrogenation reactions, metalation reaction, Michael addition, and formylation reactions. The presented information may serve as a valuable resource for researchers working in the field of medicinal chemistry and drug discovery, stimulating further exploration and development of this intriguing scaffold. [ABSTRACT FROM AUTHOR]

The catalytic hydrogenation of CO2 to formate was achieved using the previously reported dichloro(η6‐p‐cymene){diphenyl(3‐methyl‐2‐indolyl)phosphine}ruthenium (1) as a catalyst under mild conditions. In this complex, the phosphorus‐based ligand adopts a κ1‐P coordination mode. The catalytic activity was achieved in the presence of DBU as a base providing a TONmax value of 3,800. In order to explore potential transformations occurring within the catalytic reactions, a series of stoichiometric tests were performed. Complex 1 was reacted with DBU to form chloro(η6‐p‐cymene){diphenyl(3‐methyl‐2‐indolide)phosphine}ruthenium (2). Structural characterization of complex 2 confirmed a κ2‐P,N coordination mode for the ligand resulting in a four membered metallacycle. Reaction of 2 with H2 led to the formation of hydrochloro(η6‐p‐cymene){diphenyl(3‐methyl‐indolyl)phosphine}ruthenium (3), albeit not with a clean conversion. This is the product resulting from the formal addition of hydrogen across the Ru−N bond of the metallacycle. Complex 3 was also synthesized via an alternative route involving the reaction of complex 1 with Me2NH • BH3 as a means of converting Ru−Cl to Ru−H [ABSTRACT FROM AUTHOR]

The utilization of liquid organic hydrogen carrier (LOHC) based on acetophenone has been considered a promising approach for high energy density hydrogen storage, but its industrial application is limited by the low reaction and mass transfer rates observed in conventional reactors. Microreactors have the potential to promote hydrogen storage technology, and, in this study, we propose a tubular reactor coupled with a gas/liquid microdispersion module. Via generating microbubbles prior to the flow of gas and liquid reactants in the tubular reactor, our designed reactor facilitates enhanced gas/liquid interaction mass transfer, thereby improving hydrogenation reaction characteristics. To evaluate the performance of this intensified trickle bed reactor, we investigated the hydrogenation of acetophenone (AP) to 1-phenylethanolis. The results demonstrate that compared to traditional trickle bed reactors, the designed hydrogenation reactor exhibits superior performance under pressures below 2 MPa, with an absence of byproducts, increased conversion and selectivity of AP, and an achieved hydrogen storage rate reaching 0.095 mol H 2 / g Pd / min. [Display omitted] • An intensified hydrogenation reactor was proposed for efficient hydrogen storage. • A gas/liquid micro-dispersion system has been incorporated into a tubular reactor. • The reaction performance of reactors is evaluated using acetophenone hydrogenation. • The intensified reactor shows a nearly twofold increase in hydrogen storage rate. [ABSTRACT FROM AUTHOR]

The MoS2 nanosheets are acquired via a facile hydrothermal strategy, and the M/MoS2 (M = Pt, Rh, Pd, Ru) samples are gained by impregnation. By comparing the catalytic behaviors of these catalysts for p-nitroacetophenone selective hydrogenation, it is found that the catalytic property and selectivity for one −NO2 group hydrogenation of Ru/MoS2 outperform those of other as-prepared catalysts. In addition, the Ru/MoS2 catalysts with various Ru contents (0.37, 0.88, or 2.45 wt %) are used for 3-nitrostyrene selective hydrogenation, and the results show that 0.88 wt % Ru/MoS2 displays the highest catalytic activity (turnover frequency) of TOF = 118.4 h–1 (TOF = 64.2 h–1 for 0.37 wt %Ru/MoS2 and TOF = 61.7 h–1 for 2.45 wt %Ru/MoS2) under the reaction conditions of 100 °C, 3.0 MPa H2, and 1 h. The nanostructure characterization of the as-prepared catalysts (XRD, XPS, TEM, HRTEM, H2-TPD, XAS, AC-STEM, AC-STEM-EDX elemental mapping, and line scanning) demonstrate that Ruδ+ single atoms and Ru clusters are well dispersed on the support. Moreover, 0.88 wt % Ru/MoS2 exhibits extremely high selectivity of one −NO2 group hydrogenation (∼100%) at high conversion for other selected nitroaromatics' hydrogenation, such as nitrobenzene, 2-chloronitrobenzene, 1,3-dinitrobenzene, 3-nitrostyrene, p-nitroacetophenone, and p-nitrobenzonitrile. This is mainly due to the fact that Ru is present with single atoms and clusters, producing the synergism of Ruδ+ single atoms, Ru clusters, and MoS2 nanosheets. And the synergism mechanism is given below: hydrogen is preferentially adsorbed and activated at Ru clusters (forming activated H* species), the −NO2 group is easily adsorbed and activated at Ruδ+ single atoms (charge interaction between electrons from O in −NO2 and positive charge from Ruδ+ single atoms), and H* transfers to Ruδ+ single atoms by the hydrogen spillover effect of the MoS2 nanosheets, reacting with the −NO2 group, forming desired aromatic amines. [ABSTRACT FROM AUTHOR]

The functionalization of silica supports with isonicotinamide (NIC) facilitated the stabilization of small (3.5 nm), spherical cobalt nanoparticles (CoNPs) used in catalytic hydrogenation. Various silica matrices, including amorphous, mesoporous, and non‐porous ones, were synthesized and post‐grafted with NIC to serve as ligands for stabilizing CoNPs. Comprehensive characterization techniques were employed to fully analyze the prepared materials, which were then utilized in the catalytic hydrogenation of acetophenone, serving as a benchmark reaction to assess the impact of different silica supports on catalysis. The porosity and surface nature of the silica matrices played crucial roles in anchoring the amide ligand, and the presence of the ligand was essential for stabilizing the nanoparticles. Among the catalysts tested, CoNPs@SBA‐15/NIC exhibited the highest catalytic activity and demonstrated excellent performance in the hydrogenation of alkenes, nitriles, ketones, and quinoline under relatively mild conditions. No significant alteration in catalyst morphology or leaching of metal was observed after the reaction. Notably, this catalytic system achieved turnover numbers comparable to those of homogeneous cobalt catalysts. Additionally, one‐pot tandem reductive amination reactions starting from aldehydes and involving both amines and nitrobenzene yielded secondary and tertiary amines in good yields, highlighting the robustness and versatility of the catalyst. [ABSTRACT FROM AUTHOR]

cis,cis-Muconic acid (MA) is a bio-based chemical that can be converted to direct replacement chemicals or performance-advantaged bioproducts. We recently engineered the bacterium Pseudomonas putida KT2440 for the co-utilization of glucose and xylose to produce MA. This study evaluates the effect of additional genetic modifications, media composition, and bioprocess strategy on MA titer, productivity, and yield in bioreactor cultivations. We achieve a MA titer of 47.2 g L−1, a productivity of 0.49 g L−1 h−1, and a yield of 0.50 C-mol C-mol−1 from glucose and xylose supplemented with 5% (v/v) corn steep liquor with a P. putida strain harboring the deletion of gacS. Additionally, we demonstrate efficient MA production from corn stover-derived sugars and scalability to 150 L bioreactors. Techno-economic analysis and life cycle assessment predict that adipic acid, derived from catalytic hydrogenation of MA, can achieve a selling price as low as $2.60 per kg, approaching cost parity and reducing greenhouse gas emissions by up to 80% relative to fossil carbon-based adipic acid. [ABSTRACT FROM AUTHOR]

Hydrogenations are fundamentally and industrially important reactions that are atom economical paths to synthesize value‐added products from feedstock chemicals. The cooperative effects of two or more metal centers in multimetallic active sites is a successful strategy to activate small molecules and facilitate catalytic reactions, and this strategy has been recently applied to catalytic hydrogenation reactions. Furthermore, heterobimetallic complexes have been well‐documented to provide novel reaction pathways and improved selectivity, compared to their homo‐bimetallic and monometallic analogues. This minireview provides a historical perspective on the development of heterobimetallic catalysts for the hydrogenation of unsaturated substrates and describes recent developments in this burgeoning research area. [ABSTRACT FROM AUTHOR]

Since catalytic hydrogenation of nitroarenes is of great significance in chemical industry, it is imperative to develop an inexpensive and efficient catalyst. To develop high performance catalysts for hydrogenation of nitroarenes, Co-Ce-@Salen/Melamine was prepared by mixing Co-Ce-@Salen complex with melamine in 1:1 mol ratio in a mortar and grinded completely. Further, Co/CN-CeO2-Melm-T was fabricated via pyrolysis of Co-Ce-@Salen/Melamine precursor in existence of argon atmosphere. Upon Co/CN-CeO2-Melm-T3 were applied for catalysis on the reaction of hydrogenation of nitroarenes, it exhibited outstanding catalytic performance in terms of catalytic activity, selectivity, universality and reusability for hydrogenation of nitroarenes. Spectral analysis revealed that the synergistic interaction among highly dispersed metallic Co for the dispersion and activation of hydrogen, unique surface site of CeO2 for oxygen vacancies, high absorbance ability originated from alkalinity and unique high surface area of Co/CN-CeO2-Melm-T3 dominated the highly catalytic activity for the reaction of hydrogenation of nitroarenes. Notably, 3d-4f hetero-metal coordination polymers have seldom been directly employed as a precursor for preparation of inexpensive hetero-metal catalyst. Therefore, this tactic provided an alternative route to fabricate 3d-4f inexpensive hetero-metallic heterogeneous catalyst for hydrogenation of nitroarenes with high atomic economy. [ABSTRACT FROM AUTHOR]

The cheap non-noble Cu–SiO2-based nanocatalysts are under intensive study in different reactions resulting in useful chemicals, yet their application in environment protection is poorly studied. In the present work, the influence of the Cu loading (3–15 wt%) on the catalytic behavior of Cu/SiO2 materials was first precisely studied in the hydrogenation of hazardous trinitrobenzene to valuable aromatic amines with molecular hydrogen. The catalysts have been synthesized by the method of deposition–precipitation using urea. The catalyst characterization by XRD, TPR-H2, SEM, TEM, and N2 adsorption methods confirmed that they include nanoparticles of the micro-mesoporous chrysocolla-like phase supported in the mesopores of a commercial SiO2 carrier, as well as revealed formation of the highly dispersed CuO phase in the sample with the highest Cu loading. Variation in reaction conditions showed the optimal ones (170 °C, 1.3 MPa H2) resulting in complete trinitrobenzene conversion with a triaminobenzene yield of 65% for the catalyst with a 15% Cu loading, and the best yield of 82% was obtained over the catalyst with 10% Cu calcined at 600 °C. The results show the potential of Cu phyllosilicate-based catalysts for the utilization of trinitroaromatic compounds via catalytic hydrogenation to amines and their possible applications in a remediation treatment system. [ABSTRACT FROM AUTHOR]

Ni-W catalysts find extensive application in catalysis; however, the impact of diverse morphologies on their catalytic activity remains a relatively unexplored area. Using hydrothermal/solvothermal synthesis methods, we successfully synthesized Ni-W catalysts with various morphologies, including sheet-like, sphere-like, rod-like, flower-like, and particulate-like structures. Comprehensive investigations into the influence of morphology on the catalytic activity of these Ni-W catalysts were conducted, employing techniques such as SEM, XRD, XPS, TG-DTG, BET, H2-TPR, and H2-TPD. Remarkably, the flower-like Ni-W catalyst displayed exceptional catalytic properties in ethylbenzene hydrogenation, exhibiting not only high hydrogenation activity but also superior sulfur resistance. Consequently, the flower-like Ni-W catalyst holds great potential for applications in industrial catalysis. [ABSTRACT FROM AUTHOR]

α-Hydroxy-benzylphosphonates obtained by the Pudovik reaction of substituted benzaldehydes and dialkyl phosphites were added to the triple bond of dialkyl acetylenedicarboxylates. Optimum conditions involved a 24 hours stirring in the presence of 10% diazabicycloundecene in dichloromethane to afford the adducts as a mixture of predominant E - and a minor Z -isomers in 75–90% yields after flash chromatography. The structures of the geometrical isomers were confirmed by NOE- and ROE-measurements. Catalytic hydrogenation of the olefinic moiety of the adducts led to the diastereoisomers of corresponding saturated derivatives. [ABSTRACT FROM AUTHOR]

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• Co0- Coδ+ dual phase nanoparticles with controlled compositions were prepared by modifying support nature and pre-activation condition. • Support nature strongly affects active species concentration. Alumina enhances Coδ+ sites and magnesia promotes Co0 sites, while MgO-MgAl 2 O 4 forms dual-phase Co0- Coδ+ nanoparticles. • Moderate reduction temperature (400 °C) produced both Coδ+ and Co0 sites with a homogeneous distribution and close proximity favors ethanol selectivity. • 20 mol% Co/MgO-MgAl 2 O 4 catalyst demonstrated a maximum ethanol selectivity of 17.1 % (C mol% basis). Catalytic hydrogenation of CO 2 to ethanol is a promising solution to address the greenhouse gas (GHG) emissions, but many current catalysts face efficiency and cost challenges. Cobalt based catalysts are frequently examined due to their abundance, cost-efficiency, and effectiveness in the reaction, where managing the Co0 to Coδ+ ratio is essential. In this study, we adjusted support nature (Al 2 O 3 , MgO-MgAl 2 O 4 , and MgO) and reduction conditions to optimize this balance of Co0 to Coδ+ sites on the catalyst surface, enhancing ethanol production. The selectivity of ethanol reached 17.9% in a continuous flow fixed bed micro-reactor over 20 mol% Co@MgO-MgAl 2 O 4 (CoMgAl) catalyst at 270 °C and 3.0 MPa, when reduced at 400 °C for 8 h. Characterisation results coupled with activity analysis confirmed that mild reduction condition (400 °C, 10% H 2 balance N 2 , 8 h) with intermediate metal support interaction favoured the generation of partially reduced Co sites (Coδ+ and Co0 sites in single atom) over MgO-MgAl 2 O 4 surface, which promoted ethanol synthesis by coupling of dissociative (CH x *)/non-dissociative (CH x O*) intermediates, as confirmed by density functional theory analysis. Additionally, the CoMgAl, affordably prepared through the coprecipitation method, offers a potential alternative for CO 2 hydrogenation to yield valuable chemicals. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • CuCe-BTC was synthesized at room temperature for the initial time utilizing TEA. • Cu and Ce have a metal–metal interaction with the equation Cu2++Ce3+=Cu++Ce4+. • Electron transfer from Ce to Cu enhances H 2 chemisorption and C C activation on Cu. • Catalysts exhibit superior properties in hydrogenation reactions under mild conditions. Modulating the electron distribution between active sites in metal–organic frameworks (MOFs) offers a promising strategy for optimizing their catalytic performance. In this study, we employed a novel heterovalent substitution strategy to synthesize bimetallic organic frameworks (Cu x Ce y -BTC) that feature dual active sites with copper (Cu) and cerium (Ce), Our objective was to achieve efficient hydrogenation of dicyclopentadiene (DCPD) by regulating the electron transfer between the valence-variable Cu and Ce species. The designed Cu x Ce y -BTC were characterized using various spectroscopic and microscopic techniques, along with density functional theory (DFT) calculations, confirming the successful incorporation of bimetallic nodes within the framework structure and the electron transfer between them. The transfer of electrons from the less electronegative Ce to the Cu sites promotes the chemisorption of hydrogen gas (H 2) on the electron-rich Cu sites, thereby optimizing the activation of the C C bond in DCPD. The Cu 4 Ce-BTC catalyst demonstrated exceptional performance, achieving complete conversion of DCPD and significantly surpassing monometallic MOFs. Moreover, we proposed a plausible pathway for the hydrogenation of DCPD. This work highlights the synergistic effects between bimetallic centers and offers a novel strategy to improve the MOFs' catalytic activity by modulating electron distribution between dual active sites. [ABSTRACT FROM AUTHOR]

• Nitrobenzene was completely converted to aniline by using PdO/TiO 2 as catalysts with an ultra-low apparent activation energy. • Active hydrogen species were perceived as dominant species which fully came from NaBH 4. • The initial PdO nanoparticles in PdO/TiO 2 provided the adsorption sites for nitro groups. • The Pd/PdO/TiO 2 would be formed in situ by adding NaBH 4. • The Pd nanoclusters would activate NaBH 4 to generate active hydrogen species to attack the adsorbed nitro groups. The reduction of nitrobenzene to aniline is very important for both pollution control and chemical synthesis. Nevertheless, difficulties still remain in developing a catalytic system having high efficiency and selectivity for the production of aniline. Herein, it was found that PdO nanoparticles highly dispersed on TiO 2 support (PdO/TiO 2) functioned as a highly efficient catalyst for the reduction of nitrobenzene in the presence of NaBH 4. Under favorable conditions, 95% of the added nitrobenzene (1 mmol/L) was reduced within 1 min with an ultra-low apparent activation energy of 10.8 kJ/mol by using 0.5%PdO/TiO 2 as catalysts and 2 mmol/L of NaBH 4 as reductants, and the selectivity to aniline even reached up to 98%. The active hydrogen species were perceived as dominant species during the hydrogenation of nitrobenzene by the results of isotope labeling experiments and ESR spectroscopic. A mechanism was proposed as follows: PdO activates the nitro groups and leads to in-situ generation of Pd, and the generated Pd acts as the reduction sites to produce active hydrogen species. In this catalytic system, nitrobenzene prefers to be adsorbed on the PdO nanoparticles of the PdO/TiO 2 composite. Subsequently, the addition of NaBH 4 results in in-situ generation of a Pd/PdO/TiO 2 composite from the PdO/TiO 2 composite, and the Pd nanoclusters would activate NaBH 4 to generate active hydrogen species to attack the adsorbed nitro groups. This work will open up a new approach for the catalytic transfer hydrogenation of nitrobenzene to aniline in green chemistry. [Display omitted] [ABSTRACT FROM AUTHOR]

Supramolecular complexes carrying reducing agents were crystallized on the surface of nitrogen-doped hollow carbon spheres to in-situ create highly dispersed supported nano-palladium to promote thermal/electrocatalytic reduction reaction. [Display omitted] • An innovative strategy for the preparation of highly dispersed nanometals was developed. • Pd/NHCSs was prepared by combining host–guest assembly and in-situ reduction technology. • Pd/NHCSs can promote the efficient hydrogenation of nitroaromatic biomass. • Pd/NHCSs can promote the efficient reduction of nitrate to ammonia. To promote the greening and economization of industrial production, the development of advanced catalyst manufacturing technology with high activity and low cost is an indispensable part. In this study, nitrogen-doped hollow carbon spheres (NHCSs) were used as anchors to construct a supramolecular coating formed by the self-assembly of boron clusters and β -cyclodextrin by surface crystallization strategy, with the help of the weak reducing agent characteristics of boron clusters, highly dispersed ultra-small nano-palladium particles were in-situ embedded on the surface of NHCSs. The deoxygenation hydrogenation of nitroaromatics and the reduction of nitrate to ammonia were used as the representatives of thermal catalytic reduction and electrocatalytic reduction respectively. The excellent properties of the constructed Pd/NHCSs were proved by the probe reaction. In the catalytic hydrogenation of nitroaromatics to aminoaromatics, the reaction kinetic rate and activation energy are at the leading level. At the same time, the constructed Pd/NHCSs can also electrocatalytically reduce nitrate to high value-added ammonia with high activity and selectivity, and the behavior of Pd/NHCSs high selectivity driving nitrate conversion was revealed by density functional theory and in situ attenuated total reflection Fourier transform infrared (ATRFTIR) technique. These results all reflect the feasibility and superiority of in-situ anchoring ultra-small nano-metals as catalysts by surface crystallization to build a supramolecular cladding with reducing properties, which is an effective way to construct high-activity and low-cost advanced catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] In the last decades, 4-nitrophenol is regarded as one of highly toxic organic pollutants in industrial wastewater, which attracts great concern to earth sustainability. Herein, atomically dispersed ternary FeCoNb active sites were incorporated into nitrogen-doped honeycomb-like mesoporous carbon (termed FeCoNb/NHC) by a two-step pyrolysis strategy, whose morphology, structure and size were characterized by a set of techniques. Further, the catalytic activity and reusability of the as-prepared FeCoNb/NHC were rigorously examined by using 4-NP catalytic hydrogenation as a proof-of-concept model. The influence of the secondary pyrolysis temperature on the catalytic performance was investigated, combined by illuminating the catalytic mechanism. The resultant catalyst exhibited significantly enhanced catalytic features with a normalized rate constant (k app) of 1.2 × 104 min-1g−1 and superior stability, surpassing the home-made catalysts in the control groups and earlier research. This study provides some constructive insights for preparation of high-efficiency and cost-effectiveness single-atom nanocatalysts in organic pollutants environmental remediation. [ABSTRACT FROM AUTHOR]

[Introduction] CO2 catalytic hydrogenation for fuel synthesis is an economically feasible and large-scale implementable technology for CO2 utilization, which can solve the problems of environment and resource shortage, and has gained wide attention in recent years. In this work, a microchannel reactor for CO2 catalytic hydrogenation to synthesize hydrocarbon fuels is developed. [Method] Based on the design concept of thermodynamic calculation, catalyst preparation, reactor design, structure optimization and performance testing, an anlysis was carried out. [Result] The thermodynamic analysis shows that hydrocarbon fuels can be produced from CO2 catalytic hydrogenation. Six iron-based catalysts are developed to improve the reaction rate of hydrocarbon fuel synthesis. Based on the computational fluid dynamics (CFD) simulation, the structure of the microchannel reactor is designed and optimized. The microchannel reactor has the advantages of simple-compact structure and strong heat-mass transfer capability. The experimental results show that the Zn-Fe catalyst exhibits the best performance of CO2 catalytic hydrogenation for the synthesis of low-carbon olefins. CO2 conversion and low-carbon olefins selectivity are 32% and 44% respectively. [Conclusion] The microchannel reactor designed in this work has the dual functions of CO2 utilization for hydrocarbon fuel synthesis, which is of great significance to China's response to climate change, the realization of the dual-carbon target and the development of hydrocarbon fuel industry.

Catalytic transfer hydrogenation of levulinic acid (LA) to γ‐valerolactone (GVL) was attractive in biomass conversions since GVL is highly useful in different applications, such as polymer synthesis, fuel, and food. Various catalytic systems were reported for the reaction, yet harsh reaction conditions were generally required, which could restrict the scaling up of the reaction. Herein, we developed an effective and green bi‐solvent system of isopropanol/water for the catalytic transfer hydrogenation of LA to GVL over a ruthenium–phosphorous carbon (Ru‐PC) catalyst. It was found that the presence of water in the solvent system promoted the production of GVL from LA. The effect of isopropanol/water ratios and other reaction conditions were investigated, exhibiting that 93.8% yield of GVL was achieved using isopropanol/water ratio of 2.5:2.5 at 140 °C for 4 h and over Ru‐PC catalyst. Combining water and organic solvent not only reduced the usage of organic solvent but also created an effective bi‐solvent system for catalytic reactions. [ABSTRACT FROM AUTHOR]

The hydrogenation of magnesite to CH 4 and MgO offers a powerful approach for CO 2 direct utilization. To deepen the understanding of the reaction mechanisms, (Mg 5 (CO 3) 4 (OH) 2 (H 2 O) 4 was selected as a model compound to gain insights into carbonate hydrogenation. A novel Ni/Fe/ZrO 2 catalyst with ferromagnetic properties was employed to facilitate the magnetic separation of the catalyst from the solid products. Thermodynamic simulation and experiments were conducted to address key issues such as gas evolution during catalytic hydrogenation, the effects of catalyst on CH 4 selectivity, and the separation of solid products and catalyst. The results indicate that lower temperatures favor CH 4 formation, whereas higher temperatures favor CO formation. Increasing Ni loading can enhance the CH 4 selectivity. With the presence of 10Ni/Fe/ZrO 2 catalyst, 100% CH 4 selectivity can be achieved at 300 °C. Moreover, 10Ni/Fe/ZrO 2 catalyst exhibits high magnetic responsiveness, facilitating the solid separation and the recycle of the catalyst. • A novel route for the hydrogenation of magnesite to produce CH 4 and MgO is proposed. • A ferromagnetic Ni/Fe/ZrO 2 catalyst enables efficient separation of the catalyst and product. • Low temperature favors CH 4 formation, while high temperature favors CO formation. • 100% CH 4 selectivity can be achieved at 300 °C with the presence of 10Ni/Fe/ZrO 2. [ABSTRACT FROM AUTHOR]

Frustrated Lewis pairs (FLPs), composed of spatially hindered Lewis acids and bases, are promising catalysts for the catalytic hydrogenation of unsaturated organic substrates, but the lack of reusability limits their development. The functionalization of solid materials with molecular FLP is a promising method for preparing heterogeneous FLP catalysts. In this work, a magnetically recyclable FLP catalyst was successfully prepared for the reductive carbonyl compounds to the corresponding alcohols. FLP of 2‐Ph2PPhCHO/B(C6F5)3 was grafted into NH2‐MIL‐101@Fe3O4 composite material through an aldehyde‐amine condensation reaction. The as‐prepared FLP‐NH‐MIL‐101@Fe3O4 exhibited remarkable catalytic activity for aldehyde/ketone carbonyl compounds. In addition, FLP‐NH‐MIL‐101@Fe3O4 displays outstanding magnetic recyclability and can be reused 8 times without loss of activity. [ABSTRACT FROM AUTHOR]

While supported metal nanoparticles (NPs) have shown significant promise in heterogeneous catalysis, precise control over their interaction with the support, which profoundly impacts their catalytic performance, remains a significant challenge. In this study, Pt NPs are incorporated into thioether‐functionalized covalent organic frameworks (denoted COF‐Sx), enabling precise control over the size and electronic state of Pt NPs by adjusting the thioether density dangling on the COF pore walls. Notably, the resulting Pt@COF‐Sx demonstrate exceptional selectivity (> 99 %) in catalytic hydrogenation of p‐chloronitrobenzene to p‐chloroaniline, in sharp contrast to the poor selectivity of Pt NPs embedded in thioether‐free COFs. Furthermore, the conversion over Pt@COF‐Sx exhibits a volcano‐type curve as the thioether density increases, due to the corresponding change of accessible Pt sites. This work provides an effective approach to regulating the catalysis of metal NPs via their microenvironment modulation, with the aid of rational design and precise tailoring of support structure. [ABSTRACT FROM AUTHOR]

The development of base metal catalysts capable of CO2 hydrogenation is a challenge and a necessity to progress from the scarce noble metal catalysts. In this regard, we report herein the first non-phosphine-based Ni complex, supported by a "carbazolato-bis-NHC" pincer ligand framework, for efficient catalytic hydrogenation of CO2 to formate. A tailored combination of the Ni complex as a catalyst, DBU as a base, and Zn(OAc)2 as an additive offered enhanced activity leading to a TON up to 5476 and an excellent yield up to 92% for the formate product from a reaction on ∼27 mmol scale. [ABSTRACT FROM AUTHOR]

The catalytic hydrogenation of carbon dioxide to formate is of great interest due to its significant role in CO2 utilization. In this study, a novel heterogeneous Ru(III) catalyst was prepared by immobilizing RuCl3 on a porous organic polymer (POP) obtained from 1,4-phthalaldehyde (PTA) and 4,4'-biphenyldicarboxaldehyde (BPDA) with melamine. A copolymerization strategy utilizing monomers of varying lengths was employed to prepare the POP-supported Ru catalyst with adjustable porosity. The optimization of the framework porosity resulted in enhanced CO2 affinity, accelerated mass transfer, and a remarkable enhancement in catalytic activity. A high turnover number (TON) of 2458 was achieved for the CO2 hydrogenation to formate in 2 h with catalyst Cat-3 under 3 MPa (CO2/H2 = 1: 1) at 120 °C in 1 M Et3N aqueous solution. Moreover, the Cat-3 demonstrated good recyclability and was able to be reused for five consecutive runs, resulting in a high total TON of 9971. [ABSTRACT FROM AUTHOR]

Phosphine‐ligated transition metal complexes play a pivotal role in modern catalysis, but our understanding of the impact of ligand counts on the catalysis performance of the metal center is limited. Here we report the synthesis of a low‐coordinate mono(phosphine)‐Rh catalyst on a metal‐organic layer (MOL), P‐MOL • Rh, and its applications in the hydrogenation of mono‐, di‐, and tri‐substituted alkenes as well as aryl nitriles with turnover numbers (TONs) of up to 390000. Mechanistic investigations and density functional theory calculations revealed the lowering of reaction energy barriers by the low steric hindrance of site‐isolated mono(phosphine)‐Rh sites on the MOL to provide superior catalytic activity over homogeneous Rh catalysts. The MOL also prevents catalyst deactivation to enable recycle and reuse of P‐MOL • Rh in catalytic hydrogenation reactions. [ABSTRACT FROM AUTHOR]

A full selectivity control over the catalytic hydrogenation of nitroaromatics leads to the production of six possible products, i.e., nitroso, hydroxylamine, azoxy, azo, hydrazo or aniline compounds, which has however not been achieved in the field of heterogeneous catalysis. Currently, there is no sufficient evidence to support that the catalytic hydrogenation of nitroaromatics with the use of heterogeneous metal catalysts would follow the Haber's mechanistic scheme based on electrochemical reduction. We now demonstrate in this work that it is possible to fully control the catalytic hydrogenation of nitroaromatics into their all six products using a single catalytic system under various conditions. Employing SnO2‐supported Pt nanoparticles facilitated by the surface coordination of ethylenediamine and vanadium species enabled this unprecedented selectivity control. Through systematic investigation into the controlled production of all products and their chemical reactivities, we have constructed a detailed reaction network for the catalytic hydrogenation of nitroaromatics. Crucially, using oxygen‐isolated characterization techniques is essential for identifying unstable compounds such as nitroso, hydroxylamine, hydrazo compounds. The insights gained from this research offer invaluable guidance for selectively transforming nitroaromatics into a wide array of functional N‐containing compounds, both advancing fundamental understanding and fostering practical applications in various fields. [ABSTRACT FROM AUTHOR]

The development of base metal catalysts capable of CO2 hydrogenation is a challenge and a necessity to progress from the scarce noble metal catalysts. In this regard, we report herein the first non-phosphine-based Ni complex, supported by a "carbazolato-bis-NHC" pincer ligand framework, for efficient catalytic hydrogenation of CO2 to formate. A tailored combination of the Ni complex as a catalyst, DBU as a base, and Zn(OAc)2 as an additive offered enhanced activity leading to a TON up to 5476 and an excellent yield up to 92% for the formate product from a reaction on ∼27 mmol scale. [ABSTRACT FROM AUTHOR]

A new hydroxo‐bridged ruthenium (II) complex [{Ru(η6‐p‐cymene)(iPr2P−O)}2(μ‐OH)]Cl (2) has fortuitously been isolated from the reaction between the known ruthenium(II) complex [RuCl2(η6‐p‐cymene)(iPr2P‐OH)] (1) in either CDCl3 or CHCl3 solutions in the presence of excess DBU (1,8‐diazabicyclo(5.4.0)undec‐7‐ene) at room temperature. Complex 2 is only formed under specific conditions as an orange‐colored air and moisture stable binuclear complex. It is formed via the deprotonation of the P−OH unit in [RuCl2(η6‐p‐cymene)(iPr2P‐OH)]. Complex 2 has been fully characterized by spectroscopic and analytical methods. Its structure was determined by single crystal X‐ray diffraction which reveals a boat‐shaped motif containing a bridging hydroxide unit which undergoes hydrogen bonding with a chloride counterion. Complex 2 was utilized as a catalyst for the hydrogenation of CO2 to formic acid salt using molecular hydrogen. The catalytic reactions were performed at 100 °C in THF in the presence of DBU as a base to isolate [DBU+H][OC(O)H] salt as the final product. Using catalyst loadings down to 0.01 mol%, it was possible to hydrogenate gaseous CO2 with TONs up to 9900. [ABSTRACT FROM AUTHOR]