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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]

Cd-doped ZrO2 catalyst has been found to have high selectivity and activity for CO2 hydrogenation to methanol. In this work, density functional theory calculations were carried out to investigate the microscopic mechanism of the reaction. The results show that Cd doping effectively promotes the generation of oxygen vacancies, which significantly activate the CO2 with stable adsorption configurations. Compared with CO2, gaseous H2 adsorption is more difficult, and it is mainly dissociated and adsorbed on the surface as [HCd–HO]* or [HZr–HO]* compact ion pairs, with [HCd–HO]* having the lower energy barrier. The reaction pathways of CO2 to methanol has been investigated, revealing the formate path as the dominated pathway via HCOO* to H2COO* and to H3CO*. The hydrogen anions, HCd* and HZr*, significantly reduce the energy barriers of the reaction. [ABSTRACT FROM AUTHOR]

Cd-doped ZrO2 catalyst has been found to have high selectivity and activity for CO2 hydrogenation to methanol. In this work, density functional theory calculations were carried out to investigate the microscopic mechanism of the reaction. The results show that Cd doping effectively promotes the generation of oxygen vacancies, which significantly activate the CO2 with stable adsorption configurations. Compared with CO2, gaseous H2 adsorption is more difficult, and it is mainly dissociated and adsorbed on the surface as [HCd–HO]* or [HZr–HO]* compact ion pairs, with [HCd–HO]* having the lower energy barrier. The reaction pathways of CO2 to methanol has been investigated, revealing the formate path as the dominated pathway via HCOO* to H2COO* and to H3CO*. The hydrogen anions, HCd* and HZr*, significantly reduce the energy barriers of the reaction. [ABSTRACT FROM AUTHOR]

Isolated platinum(II) ions anchored at acid sites in the pores of zeolite HZSM-5, initially introduced by aqueous ion exchange, were reduced to form platinum nanoparticles that are stably dispersed with a narrow size distribution (1.3 ± 0.4 nm in average diameter). The nanoparticles were confined in reservoirs within the porous zeolite particles, as shown by electron beam tomography and the shape-selective catalysis of alkene hydrogenation. When the nanoparticles were oxidatively fragmented in dry air at elevated temperature, platinum returned to its initial in-pore atomically dispersed state with a charge of +2, as shown previously by X-ray absorption spectroscopy. The results determine the conditions under which platinum is retained within the pores of HZSM-5 particles during redox cycles that are characteristic of the reductive conditions of catalyst operation and the oxidative conditions of catalyst regeneration.

On account of slowly reducing of fossil-fuel, profitable utilization of available fossil-fuel to produce electric power is a major concern for electric power producers. Here, short-period fuel constrained power, heat, natural gas and clean water augmentation planning (FCPHGWAP) of isolated microgrid considering carbon capture is presented. FCPHGWAP finds out the most economical and consistent augmentation plan to meet the prophesied power, heat, natural gas and clean water demand over a short-term time horizon whilst satisfying several technical as well as societal constraints. An archetypical system having extant diesel generators (DGs), PVT panel, wind turbine generator (WG), micro-cogeneration unit (MCU), battery energy storage system (BESS), plug-in electric vehicles (PEVs), thermal energy storage system, natural gas storage unit, carbon capture unit (CCU), electrolyzer, hydrogen storage unit and aspirant PVT panel, WGs, MCUs and PEVs is taken into consideration. Self-organizing hierarchical particle swarm optimizer with time-varying acceleration coefficients and grey wolf optimization are used to solve this FCPHGWAP problem. It is observed that net present value having fuel constraints is less than that of without fuel constraints. • Water, gas, power and heat generation expansion planning of isolated MG is studied. • Fuel constraints of DGs and MCUs are taken into consideration. • Clean water, natural gas, heat and power reserve margin are taken into account. • Carbon captured from MCUs and DGs is used to produce methane. • Hydrogen is generated from clean water produced by desalinating sea water. [ABSTRACT FROM AUTHOR]

In order to improve current efficieny, a novel flow and circulation electrolytic system was developed using a Pd tube cathode coated on the inside with Pd black, and packed with Pd catalyst supported on carbon fiber, which is surrounded by a platinum wire anode. This new electrochemical flow system was shown to be highly effective for the cathodic hydrogenation of unsaturated compounds and the dehalogenation of various aromatic halides, including PCB precursors. [ABSTRACT FROM AUTHOR]

Heteroleptic magnesium hydrides are important for their stoichiometric and catalytic reduction chemistry. Their primary nucleophilic site is typically the hydride, while the ancillary ligands commonly used are mostly spectators. Chemically non-innocent ligands in comparison are rarely applied on MgH as their reactivity can be complex. Milstein et al. have recently reported Mg-mediated alkyne hydrogenation by using their metal–ligand cooperation (MLC) concept on a dearomatized picolyl-based PNP pincer that is non-innocent with a nucleophilic nature. A '(PNP)MgH' is noted as the active catalyst in hydrogenation but without structural validation. Inspired by the same, we report herein a novel NNN-chelator (MesL) with a dearomatized picolyl moiety and its well-defined MgH. Having two prominent nucleophilic sites, the present MgH shows metal–ligand competition while reacting with certain electrophiles. It also distinguishes nonpolar alkynes and polar carbonyls by cleanly inserting itself into the former but not the latter. The nucleophilicities of the two sites are also probed by DFT methods and compared with Milstein's (PNP)MgH. Although the present system shows no MLC-type H2 activation, the addition of a CS2 molecule in that way is realized. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The first catalytic asymmetric total synthesis of (+)‐propolisbenzofuran B, enabled by a highly enantioselective rhodium‐catalyzed hydrogenation of a tetrasubstituted olefin, was described. Other noteworthy aspects include the construction of the central hydrodibenzo[b,d]furan core through a sequence of Zn(II)‐mediated regioselective benzofuran formation and Dieckmann condensation, as well as C‐H oxidations, involving a visible light‐induced Fe(III)‐catalyzed benzylic C(sp3)‐H oxidation. Additionally, the absolute configuration was confirmed by X‐ray analysis of a carbonate intermediate. [ABSTRACT FROM AUTHOR]

Iron sulfide catalysts could boost the hydrogenation of polycyclic aromatic hydrocarbons, and have been widely employed in direct coal liquefaction owing to their low price and good activity. In the past, the Fe deficient structure on Fe1−xS was normally considered as the active site. Herein, the promotion effect of S vacancies on the performance in the naphthalene hydrogenation reaction was revealed. Additional S vacancies on the prepared Fe1−xS catalyst were introduced by a heat‐treatment under H2. Multiple characterization techniques verified that the density of S vacancies on catalyst surface increased with the prolonged H2 treatment time, while the Fe deficient structure displayed an opposite trend. The performance in the hydrogenation of naphthalene to tetralin was used to evaluate the catalyst activity. It was found that the sequence of naphthalene conversion over catalysts was consistent with the corresponding content of S vacancies, indicating that S vacancies were more efficient active sites. DFT calculation results revealed that both molecular H2 and naphthalene exhibited a pronounced inclination towards adsorption on S vacancies as compared to intact surface of Fe1−xS. The increasing amount of S vacancies facilitated the adsorption of reactants and the weakening of naphthalene C−C bonds. [ABSTRACT FROM AUTHOR]

The semi‐hydrogenation of terminal alkynes is achieved with sodium borohydride (NaBH4) as the reductant and palladium nanowires (PdNWs) as the catalysts under ambient conditions. The reaction proceeds smoothly in the presence of only 0.32 mol % of PdNWs, giving the hydrogenated products with up to 98 % overall yields, in which 97 % are semi‐hydrogenated products. Under the optimal reaction conditions, both aromatic and aliphatic terminal alkynes have been successfully converted to the corresponding olefins with high efficiency and good selectivity. This method promotes the hydrogenation of terminal alkynes under mild conditions and opens up a window for the application of metal nanowires in organic syntheses. [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]

The recently reported electrochemical, organo‐mediator enabled deuteration of styrenes, a reaction referred to as "electrochemical deuterium atom transfer", differs mechanistically from reported direct electrochemical hydrogenations/deuterations only by a mediated, homogeneous SET to the substrates. By comparing direct vs. mediated processes in general and for styrene reduction, we display that Qiu's work does not change the concept of this chemistry. Experiments with mediators and the direct reduction of examples from the reported scope show that even electron‐rich substrates can be reduced when our direct protocol, published six months before Qiu's work, is applied. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The first catalytic asymmetric total synthesis of (+)‐propolisbenzofuran B, enabled by a highly enantioselective rhodium‐catalyzed hydrogenation of a tetrasubstituted olefin, was described. Other noteworthy aspects include the construction of the central hydrodibenzo[b,d]furan core through a sequence of Zn(II)‐mediated regioselective benzofuran formation and Dieckmann condensation, as well as C‐H oxidations, involving a visible light‐induced Fe(III)‐catalyzed benzylic C(sp3)‐H oxidation. Additionally, the absolute configuration was confirmed by X‐ray analysis of a carbonate intermediate. [ABSTRACT FROM AUTHOR]

The photocatalytic conversion of biomass‐derived compounds into value‐added chemicals presents a promising protocol for the sustainable production of renewable chemicals. Our study explores the hydrogenation of biomass model compounds under visible light illumination. Zr was incorporated into the CeO2 framework, forming a CeZrOx(1:0.5) solid solution, confirmed by powder X‐ray diffraction (PXRD) and X‐ray photoelectron spectroscopy (XPS) analyses. The light uptake capacity of the CeZrOx solid solution was characterized using UV–visible spectroscopy. Additionally, the band structure of the CeZrOx solid solution was assessed using valance band X‐ray photoelectron spectroscopy (VB‐XPS) and Ultraviolet photoelectron spectroscopy (UPS) analysis, revealing a Z‐Scheme, which was further confirmed by various control experiments. Upon decorating the CeZrOx(1:0.5) solid solution with 1 wt% palladium (Pd), the resulting 1Pd/CeZrOx(1:0.5) composite exhibited improved charge separation and enhanced visible light absorption capacity. This composite achieved ∼99% conversion of furfural to tetrahydrofurfuryl alcohol under a 15 W blue LED illumination and 0.2 MPa hydrogen. Similarly, it demonstrated ∼99% conversion of benzyl phenyl ether (BPE) to toluene and phenol under a 10 W blue LED illumination. Our findings elucidate the active sites and demonstrate the recyclability of mixed metal oxides for selective furfural hydrogenation and BPE hydrogenolysis under visible light. [ABSTRACT FROM AUTHOR]

A CO2 hydrogenation reactor based on protonic ceramic electrolysis cells (PCECs) is one of the most promising options for the efficient and clean conversion of CO2. However, insufficient performance and durability have hindered the practical application of such CO2 hydrogenation reactors. Here, fabricates a large‐area (≈10 cm2) tubular air electrode supported PCEC (AES‐PCEC) and develop a fuel electrode regeneration strategy for efficient and durable CO2 hydrogenation. The AES‐PCEC demonstrates a CO yield of 2.88 mL min−1 at 650 °C while maintaining excellent durability for over 1100 h. The high stability of the AES‐PCEC can be attributed to the robust and thin fuel electrode structure as well as the water‐mediated carbon removal regeneration mechanism. Density functional theory calculations have confirmed the regeneration mechanism facilitated by the excellent water hydration and dissociation capability of the BaCe0.4Zr0.4Y0.1Yb0.1O3‐σ. This work offers a feasible strategy to design high‐performance and durable PCEC‐based CO2 hydrogenation reactors. [ABSTRACT FROM AUTHOR]

In this paper, compositions within the TiZrAlCrMn, TiZrAlCrFe, and TiZrAlMnFe alloy systems that form the C14 Laves phase are investigated. The design, synthesis, structural, and hydrogen storage characterizations for an equiatomic and a non‐equiatomic composition for each alloy system are presented. Additionally, the further development of a thermodynamic method for the calculation of pressure‐composition‐isotherms (PCIs) is presented of C14 Laves phase alloys that absorb hydrogen by solid solution. Overall, the results shown in this paper indicate that Al‐containing multicomponent alloys can present promising hydrogen storage performance under high pressures. Nonetheless, high concentrations of aluminum in highly concentrated (equiatomic) alloys can have a negative impact on the hydrogenation properties. The Ti0.29Zr0.05Al0.05Cr0.26Mn0.35 composition showed promising hydrogenation/dehydrogenation properties. The gravimetric capacity of this alloy is ≈1.76 wt.% H2 and the PCIs measured indicate that this material has potential for high‐pressure hydrogen storage and compression applications. The use of the presented thermodynamic model for the design of multicomponent alloys is suggested. [ABSTRACT FROM AUTHOR]

In a previous study, puzzling experimental results regarding the neutralization of N effects on the bandgap energy in the hydrogenated In0.21Ga0.79As0.975N0.025 alloy were explained by theoretical investigations revealing the occurrence of a novel phenomenon: thermal annealing changes the InGaAs host‐matrix by making it able to exert a selection of the N–H complexes responsible of the N neutralization. In view of technological applications of this effect, the underlying selective host‐matrix model was carefully checked here by theoretically investigating InGaAsN alloys of different compositions ranging from Ga‐rich to In‐rich. As a most important result, such an extensive investigation inspired a comprehensive explanation of the origin of the host‐matrix effect which clarifies how the effect works, firmly establishes its occurrence, gives indications for a bandgap tuning based on a matrix design, sets conditions for its extension to other III‐V‐N alloys and suggests ways to induce fine changes of the alloy mechanical behavior. [ABSTRACT FROM AUTHOR]

N‐monomethyl amines are useful intermediates in drugs, natural products, paints. Yet their synthesis is a tremendous challenge due to their high reactivity, typically leading to overmethylation. In this contribution, a highly selective catalytic N‐methylation methodology is reported, converting urea derivatives to monomethylated amines, using a commercially available heterogeneous Pd/C catalyst and methanol as unique reagent. Methanol provides a sustainable alternative protocol for the selective preparation of mono‐methylated derivatives as it acts as both H2 and C1 sources. In addition, several control experiments were performed to provide a proposal for the mechanism, namely dehydrogenation of methanol and subsequent hydrogenation of urea derivatives, followed by reduction of the in situ formed methyl imine. Importantly, the approach is simple, highly productive and enables novel synthetic procedures for the preparation of monomethylamines from urea derivatives. [ABSTRACT FROM AUTHOR]

CO2 capture and reduction with H2 (CCR) to synthesise CH4 over dual-functional materials (DFMs) possessing CO2 capture and hydrogenation abilities has recently attracted attention as a promising methodology for utilising low-concentration CO2 in air or exhaust gases without pressure and/or temperature swing operations. Much effort has been devoted to the development of Ni-based DFMs for the CCR of CH4 formation owing to their low cost and high catalytic potential for methanation. However, previous studies have been investigated under relatively high reaction temperatures (400–600 °C) and/or pressurised H2 conditions. In addition, experiments were conducted in the absence of O2 in the simulated CO2 gas. The development of efficient Ni-based DFMs under milder and more realistic reaction conditions is still necessary. In this study, we developed La-modified Al2O3-supported Ni nanoparticles (Ni–La(X)/Al2O3, X denotes the La loading) for the selective formation of CH4 from low-concentration CO2 (1%) in a simulated gas containing O2 (20%). The optimised Ni–La(15)/Al2O3 showed 99% selectivity for CH4 formation under isothermal (350 °C) and non-pressurised conditions. The effect of the La loading amount on the CCR performance was studied using X-ray diffraction, temperature-programmed surface reactions, and steady-state CO2 hydrogenation. Furthermore, the developed Ni–La(15)/Al2O3 was applied to direct capture of ultralow concentration CO2 in air (ambient direct air capture (DAC)) and methanation. [ABSTRACT FROM AUTHOR]

The recycling and upcycling of polyethylene terephthalate (PET), the most widely used polyester plastic globally, has attracted growing attention concerning its disposal as non‐degradable waste in the natural environment. Transforming end‐of‐life PET into (bio)degradable polyester offers a novel approach to managing its waste. In this study, we introduce a simple process capable of converting waste PET into degradable polyester, polyethylene terephthalate‐polyethylene‐1,4‐cyclohexanedicarboxylate (PET‐PECHD), by partly hydrogenating the aromatic rings (x) into aliphatic ones (y). The polyesters with variable x/y compositions ranging from 100/0 to 0/100 can be achieved, and the molecular weight (Mw) can be maintained when x/y >87/13 due to the nonobvious depolymerization. Pronounced depolymerization would occur with deeper hydrogenation, which generates a blend of PET‐PECHD and polyethylene‐1,4‐cyclohexanedicarboxylate (PECHD) with lower Mw, and finally a single‐type polymer PECHD. The PET‐PECHD demonstrates comparable thermal stability and mechanical strength compared to PET, along with superior extensibility, barrier properties, and (bio)degradability in acidic, alkaline solutions, and moist soil. This research highlights the potential for cost‐effective, large‐scale production of degradable polyester from real‐life plastic waste. [ABSTRACT FROM AUTHOR]

The optically active lactams represent an important structural motif and present in a wide range of natural products, biologically active compounds and drugs. Compared to the synthesis of chiral five‐ and six‐membered lactams, the asymmetric construction of seven‐membered lactams often presents a challenge due to their consequential entropic and enthalpic barriers. Over the past few decades, substantial efforts have been devoted to this field and chemists have developed various efficient strategies for the preparation of seven‐membered lactams. In this review, we will highlight the recent advances in enantioselective formation of seven‐membered lactams and the discussion will be logically divided into three parts according to the reaction mode. The aim of this review is to familiarize the Reader with new synthetic opportunities offered by these interesting methodologies. [ABSTRACT FROM AUTHOR]

The dynamic structure evolution of heterogeneous catalysts during reaction has gained great attention recently. However, controllably manipulating dynamic process and then feeding back catalyst design to extend the lifetime remains challenging. Herein, we proposed an entropy variation strategy to develop a dynamic CuZn−Co/HEOs catalyst, in which the non‐active Co nano‐islands play a crucial role in controlling thermal effect via timely capturing and utilizing reaction heat generated on the adjacent active CuZn alloys, thus solving the deactivation problem of Cu‐based catalysts. Specifically, heat sensitive Co nano‐islands experienced an entropy increasing process of slowly redispersion during the reaction. Under such heat dissipation effect, the CuZn−Co/HEOs catalyst exhibited 95.7 % ethylene selectivity and amazing long‐term stability (>530 h) in the typical exothermic acetylene hydrogenation. Aiming at cultivating it as a catalyst with promising industrial potential, we proposed a simple regeneration approach via an entropy decreasing process. [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]

Restructuring the current energy industry towards sustainability requires transitioning from carbon based to renewable energy sources, reducing CO2 emissions. Hydrogen, is considered a significant clean energy carrier. However, it faces challenges in transportation and storage due to its high reactivity, flammability, and low density under ambient conditions. Liquid organic hydrogen carriers offer a solution for storing hydrogen because they allow for the economical and practical storage of organic compounds in regular vessels through hydrogenation and dehydrogenation. This review evaluates several hydrogen technologies aimed at addressing the challenges associated with hydrogen transportation and its economic viablity. The discussion delves into exploring the catalysts and their activity in the context of catalysts′ development. This review highlights the pivotal role of various catalyst materials in enhancing the hydrogenation and dehydrogenation activities of multiple LOHC systems, including benzene/cyclohexane, toluene/methylcyclohexane (MCH), N‐ethylcarbazole (NEC)/dodecahydro‐N‐ethylcarbazole (H12‐NEC), and dibenzyltoluene (DBT)/perhydrodibenzyltoluene (H18‐DBT). By exploring the catalytic properties of noble metals, transition metals, and multimetallic catalysts, the review provides valuable insights into their design and optimization. Also, the discussion revolved around the implementation of a hydrogen economy on a global scale, with a particular focus on the plans pertaining to Saudi Arabia and the GCC (Gulf Cooperation Council) countries. The review lays out the challenges this technology will face, including the need to increase its H2 capacity, reduce energy consumption by providing solutions, and guarantee the thermal stability of the materials. [ABSTRACT FROM AUTHOR]

Heterogeneous catalysis plays a pivotal role in the current chemical and energy vectors production. Notably, to fully utilize the intrinsic activity and selectivity of a catalyst, the chemical reactor has to be designed and operated optimally to achieve enhanced heat/mass transfer, well-defined contact time of reactants, uniform flow pattern, and high permeability. Structured catalysts are a promising strategy to overcome the major drawbacks encountered in the traditional packed-bed reactor technology due to the improved hydrodynamics in combination with enhanced heat/mass transfer. Newly emerged fiber/foam-substrates, with an entirely open 3D network structure, bring distinct advantages over the honeycomb and micro-channel contacting methods, including free radial diffusion, eddy-mixing driven heat/mass transfer, large area-to-volume ratio, and high contacting efficiency. However, how to place the nanocatalysts onto the fiber/foam-substrates is a challenging problem because the commercial washcoating method has great limitations such as the nonuniformity and easy exfoliation of coatings. This review discusses the newly developed non-dip-coating methods for the fiber/foam-structured catalysts and their promising applications in the strongly exo-/endo-thermic and/or high throughput reaction processes. [ABSTRACT FROM AUTHOR]

The selective hydrogenation of lignin-derived phenols under mild conditions is still a challenging work. In this study, 2.0 wt% Pd/γ-Al2O3 catalyst was found to show high catalytic performance for the selective hydrogenation of lignin-derived phenols, giving 100% conversion of substrate and 94.9% yield of cyclohexanols under optimized conditions. The excellent catalytic performance of the 2.0 wt% Pd/γ-Al2O3 catalyst could be possibly ascribed to its higher percentage (93.6%) of surface Pd0 species than other catalysts. The turnover number (TON) of substrate was 1363 with apparent activation energy (Ea) of 22.7 and 13.6 kJ mol−1 for the hydrogenation of 4-ethyl phenol to 4-ethyl cyclohexanone and subsequent hydrogenation for C=O bond over Pd/γ-Al2O3, respectively. The lower Ea could possibly explain the excellent catalytic activity for the full hydrogenation of 4-ethyl phenol to 4-ethyl cyclohexanol. Furthermore, this catalyst showed higher selectivity to hydrolysis and hydrogenation than to hydrogenolysis for the conversion of β-O-4, 4-O-5 and α-O-4 linked lignin-derived dimeric compounds with excellent substrate conversion and cyclohexanol product yield, offering great opportunity and potential for upgrading of lignin-derived phenols to well-defined end products. [ABSTRACT FROM AUTHOR]

The hydrogenation of m-cresol was studied across a wide temperature range, revealing complex variations in product distribution and reaction mechanisms. It has been found that the hydrogenation process predominantly yields 3-methylcyclohexanone and 3-methylcyclohexanol as primary products through ring hydrogenation (HYD) within the 140–250 ℃ temperature range. Conversely, the hydrodeoxygenation (HDO) products, toluene and methylcyclohexane, remain insignificant. More interestingly, the HYD yield is observed to diminish at elevated temperatures, with HDO becoming more dominant beyond 270 ℃. Further exploration of potential factors influencing the observed reduction in HYD yield at elevated temperatures—namely site deactivation, equilibrium limitations, and variations in surface coverage—revealed that changes in the surface adsorption of m-cresol play a critical role in the observed decrease in HYD activity, rather than site deactivation or equilibrium constraints. The order of 3-methylcyclohexanone formation with respect to m-cresol increases from 0 to 1 across the examined temperature range, suggesting m-cresol adsorption follows a simple Langmuir–Hinshelwood adsorption model where r ∼ k K C P C / (1 + K C P C) . This analysis not only advances our understanding of the temperature-dependent behavior in m-cresol hydrogenation but also lays the groundwork for future kinetic modeling, offering deeper insight into the complex dynamics of m-cresol hydrogenation. [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]

The direct conversion of furfural (FA) from biomass to pentanediols (PeDs), including 1,2-PeD and 1,5-PeD, is important for replacing fossil resources and developing bio-based polyesters from renewable sources. However, achieving high selectivity for the C–O hydrogenation of the furan ring remains a significant challenge. In this study, we synthesized a series of trimetallic CuCoLa catalysts, using a coprecipitation method with various metal ratios. The reduced CuCoLa catalyst with a metal ratio of 1/3/1, exhibited the highest activity for the selective hydrogenolysis of FA to PeDs. Under optimal reaction conditions (160 °C, 4 MPa H2 for 9 h), CuCoLa(1/3/1)-R achieved yields of 21.7% for 1,2-PeD and 50.1% for 1,5-PeD. Furthermore, the catalyst remained stable after five cycles of FA conversion to PeDs. The high selectivity for PeDs is attributed to the synergistic interaction between Cu and Co and the appropriate number of basic surface sites. [ABSTRACT FROM AUTHOR]

Hydrogenation plays an important role in the production of bulk and fine chemicals. In the present work, the hydrogenation process of 1-cyanocyclohexaneacetic acid (1-CA), a key intermediate in the chemo-enzymatic synthesis of the antiepileptic drug gabapentin, was investigated. The catalysts were screened, the operating parameters for the 1-CA hydrogenation were determined by response surface methodology, and the effects of biological impurities on the reaction and catalysts were investigated. The reaction temperature, reaction solution pH and reaction time were identified as the main factors for hydrogenation by single-factor experiments. Under the optimal reaction conditions: reaction temperature 110 °C, solution pH 12.33, reaction time 3.74 h, hydrogen pressure 2 MPa and stirring speed 500 rpm, the substrate conversion reached 100%, and the total product yield reached 96.40%, which was very close to the prediction (96.88%). It was demonstrated that biological impurities greatly affect the reaction rate of hydrogenation, as well as the activity and reusability of the catalyst, in which protein impurities lead to catalyst deactivation through cumulative deposition on the catalyst surface and within the pores. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The first asymmetric hydrogenation of acyclic tetrasubstituted α,β‐unsaturated amides has been achieved by using Rh/DuanPhos complex as a catalyst, delivering chiral β‐amino amides with two contiguous chiral centers in excellent yields and high enantioselectivities (up to 99% yield, 96% ee), which provides efficient and concise access to valuable β‐amino amide derivatives. The gram‐scale reaction and efficient transformation of β‐amino amide to β‐amino acid and β‐amino cyanide demonstrated the utility of this methodology. [ABSTRACT FROM AUTHOR]

Hydrogenated metal borides have attracted much attention due to their potential high-temperature superconductivity. Here, we propose a new strategy for hydrogen intercalation tuning the stability and superconductivity of the boron honeycomb sublattice, and predict an unprecedented layered compound Na2B2H, which hosts excellent superconductivity. Strikingly, the superconducting transition temperature (Tc) of Na2B2H reaches 42 K at ambient pressure. The Tc value can be further increase to 63 K under 5% biaxial tensile strain. The excellent superconductivity originates from the strong electron-phonon coupling between the σ-bonding bands near the Fermi level and the B-B stretching optical E′ modes. The interstitial electron localization and crystal orbitals of the H-intercalated Na ion layer well match the boron honeycomb lattice and act as a chemical template to stabilize the B layer. Furthermore, the introduction of hydrogen tuned the Fermi level, and the coupling vibration of Na and H ions effectively enhanced the dynamic stability of the structure. Na2B2H represents a new family of layered high-temperature superconductors, and the strategy of stabilizing the honeycomb boron sublattice via chemical template hosts great potential for application to more layered compounds. [ABSTRACT FROM AUTHOR]

Ambient-condition acetylene hydrogenation to ethylene (AC-AHE) is a promising process for ethylene production with minimal additional energy input, yet remains a great challenge due to the difficulty in the coactivation of acetylene and H2 at room temperature. Herein, we report a highly efficient AC-AHE process over robust sulfur-confined atomic Pd species on tungsten sulfide surface. The catalyst exhibits over 99% acetylene conversion with a high ethylene selectivity of 70% at 25 oC, and a record space-time yield of ethylene of 1123 molC2H4 molPd−1 h−1 under ambient conditions, which is nearly four times that of the typical Pd1Ag3/Al2O3 catalyst, and exhibiting superior stability of over 500 h. We demonstrate that the confinement of Pd-S coordination induces positively-charged atomic Pdδ+, which not only facilitates C2H2 hydrogenation but also promotes C2H4 desorption, thereby enabling a high conversion of C2H2 to C2H4 at room temperature while suppressing over-hydrogenation to C2H6. Ambient-condition acetylene hydrogenation to ethylene (AC-AHE) is a promising process for ethylene production yet remains a challenge. Here the authors report a highly efficient AC-AHE process over robust sulfur-confined atomic Pd species on tungsten sulfide surface, achieving over 99% conversion and 70% selectivity, with a record-breaking ethylene yield and excellent stability exceeding 500 h at 25 °C. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The first asymmetric hydrogenation of acyclic tetrasubstituted α,β‐unsaturated amides has been achieved by using Rh/DuanPhos complex as a catalyst, delivering chiral β‐amino amides with two contiguous chiral centers in excellent yields and high enantioselectivities (up to 99% yield, 96% ee), which provides efficient and concise access to valuable β‐amino amide derivatives. The gram‐scale reaction and efficient transformation of β‐amino amide to β‐amino acid and β‐amino cyanide demonstrated the utility of this methodology. [ABSTRACT FROM AUTHOR]

The search for renewable sources of energy has resulted in the focus of the use of biomass and biomass-derived platform chemicals for the generation of energy. One such chemical—furfuryl alcohol—which has several industrial applications can be obtained from furfural via hydrogenation using catalysts. Novel N^S (pzyraolyl-thio) and N^Se (pyrazolyl-selenium) bidentate ligands and their corresponding palladium(II) complexes were synthesized and evaluated as catalysts for the hydrogenation of furfural. The catalysts are active for the solventless chemoselective hydrogenation of furfural with TON around 1600 obtained. The role of the sulfur or selenium donor atoms as well as the presence of bulky groups on the catalysts influencing catalytic activity was investigated. Bulky groups present were found to slightly increase catalytic activity while the large size of selenium as compared to sulfur was not found to significantly impact catalytic activity. The complexes were found to hydrogenate furfural by homogenous means with likely palladium-bicarbonate intermediate species being observed. The recyclability of the homogenous catalysts by heterogenization using a supported ionic liquid phase (SILP) approach was investigated. [ABSTRACT FROM AUTHOR]

The selective hydrogenation of lignin-derived phenols under mild conditions is still a challenging work. In this study, 2.0 wt% Pd/γ-Al2O3 catalyst was found to show high catalytic performance for the selective hydrogenation of lignin-derived phenols, giving 100% conversion of substrate and 94.9% yield of cyclohexanols under optimized conditions. The excellent catalytic performance of the 2.0 wt% Pd/γ-Al2O3 catalyst could be possibly ascribed to its higher percentage (93.6%) of surface Pd0 species than other catalysts. The turnover number (TON) of substrate was 1363 with apparent activation energy (Ea) of 22.7 and 13.6 kJ mol−1 for the hydrogenation of 4-ethyl phenol to 4-ethyl cyclohexanone and subsequent hydrogenation for C=O bond over Pd/γ-Al2O3, respectively. The lower Ea could possibly explain the excellent catalytic activity for the full hydrogenation of 4-ethyl phenol to 4-ethyl cyclohexanol. Furthermore, this catalyst showed higher selectivity to hydrolysis and hydrogenation than to hydrogenolysis for the conversion of β-O-4, 4-O-5 and α-O-4 linked lignin-derived dimeric compounds with excellent substrate conversion and cyclohexanol product yield, offering great opportunity and potential for upgrading of lignin-derived phenols to well-defined end products. [ABSTRACT FROM AUTHOR]

Herein, methane (CH4) production in carbon dioxide (CO2) hydrogenation by hydrogen (H2) is enhanced by reducing surface carbon deposits on molybdenum carbide (Mo2C) hollow spheres. When surface carbon deposits present on Mo2C hollow spheres, CO2 conversion is 9.9%, and CO and CH4 are both produced from CO2 hydrogenation, with CO and CH4 selectivity of 58.4% and 41.6%, respectively. When surface carbon deposits absent on Mo2C hollow spheres, CO2 conversion increases to 18.6%, and CO2 hydrogenation to CH4 is enhanced, with a 100% CH4 selectivity. Reducing surface carbon deposits on Mo2C hollow spheres changes the CO2 adsorbed on Mo2C hollow spheres from a monodentate structure to a bidentate structure which prefers to undergo hydrogenation to CH4, thus enhancing CH4 formation from CO2 hydrogenation. These results open a new way to fabricate more efficient noble‐metal‐free catalysts for selective CO2 hydrogenation. [ABSTRACT FROM AUTHOR]

Secondary‐metals promotion is key to tune the CO2 hydrogenation performance of Rh‐based catalyst. We describe the addition of Cu or Co in TiO2 nanorods supported Rh catalyst (viz., RhMx/TiO2), showing significant impact on the CO2 hydrogenation activity and productivity. Cu addition can promote the partial hydrogenation to alcohols (methanol and ethanol), whereas Co led to the deep hydrogenation to alkanes (CH4, C2H6). Comparative time‐resolved in situ DRIFTS studies with H2/D2 isotopic exchange further reveal that both surface adsorbed CO* and formates could be the key reaction intermediates during the CO2 hydrogenation over RhMx/TiO2 (especially the RhCu2.5/TiO2), in which the interaction strength of CO* regulated by secondary‐metals addition was key to tune the reaction pathways and productivity. The findings suggested that rational design of active metal sites, for example the synergy between Rh and secondary‐metals, is highly needed to promote the CO insertion and CC coupling to produce ethanol. [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]

Electrocatalytic alkynol semi‐hydrogenation for the high‐value chemicals alkenol with mild conditions and carbon‐free emission is a potentially green and sustainable alternative to conventional thermocatalytic routes, which generally involves the design of electrocatalysts with high activity and high selectivity. Here, the rare‐earth single‐atom (Ln = La, Nd, Pr) coordinated Pd metallene (Ln1Pdene) is reported for electrocatalytic 2‐methyl‐3‐butyn‐2‐ol (MBY) semi‐hydrogenation reaction (MBY ESHR) to synthesis of 2‐methyl‐3‐buten‐2‐ol (MBE). Typically, in alkaline medium containing 0.1 m MBY, MBY conversion and MBE selectivity of La1Pdene are as high as ≈97% and ≈95%, respectively, with excellent electrocatalytic stability. Meanwhile, in situ infrared spectra reveal the conversion of MBY to MBE during the dynamic electrocatalytic process. Theoretical calculations reveal that the interaction between La single‐atom and Pd host triggers an unconventional transformation of the intermediate MBE* adsorption configuration during electrocatalytic hydrogenation, achieving the optimal desorption energy between La1Pd and target product and optimizing the reaction energy barriers to inhibit the over‐hydrogenation of MBE. Moreover, La single‐atom as the adsorption active site of the hydrogen supplier H2O effectively reduces the competition adsorption between the reactants MBY and H2O, rendering La single‐atom and Pd host as the synergistic co‐catalytic active sites to promote the electrocatalytic MBY semi‐hydrogenation reaction. [ABSTRACT FROM AUTHOR]

Herein, we synthesized new manganese(I) complexes coordinated with the tetradentate ligand PNNP. The complexes show higher activity and excellent substituent tolerance in contrast to their manganese counterparts and are applicable in the hydrogenation of a wide range of aromatic, aliphatic and heterocyclic ketones to their corresponding alcohols. [ABSTRACT FROM AUTHOR]

Daphenylline, a structurally unique triterpenoid Daphniphyllum alkaloid, has attracted considerable attention from the synthetic community since its isolation. Herein, we delineate an enantioselective total synthesis of (−)‐daphenylline, which is based on a gold‐catalyzed dearomatization reaction of β‐methoxynaphthalene. Other features include installation of the initial chiral stereocenter via an enantioselective rhodium‐catalyzed hydrogenation of an alkylidene‐indane derivative; construction of the other vital stereocenter by organocatalytic asymmetric Mukaiyama–Michael reaction of a structurally complex benzofused cyclohexanone; and a tandem reductive amination/amidation double cyclization reaction to assemble the distinctive azapolycyclic cage‐like architecture. [ABSTRACT FROM AUTHOR]

An atom‐economical sequential‐flow synthesis of donepezil, a widely prescribed drug for Alzheimer's disease, was accomplished using inexpensive, commercially available precursors. This achievement was made possible by reconfiguring the synthetic route to include only heterogeneous catalytic addition and condensation reactions, with a particular emphasis on skeletal transformation and bond formation through hydrogenation processes. Notably, water was the sole byproduct in this synthesis. A crucial aspect of this work was the development of appropriate continuous‐flow processes to achieve a one‐flow synthesis. This was accomplished by implementing in‐line treatments of the main reaction stream to eliminate inhibitory factors that could affect catalyst performance in the hydrogenation steps. [ABSTRACT FROM AUTHOR]

The selective hydrogenation of 5‐hydroxymethylfurfural (HMF) to 2,5‐bishydroxymethyltetrahydrofuran (BHMTHF), a vital fuel precursor and solvent, is crucial for biomass refining. Herein, we report highly selective and stable PdNi nanoalloy catalysts for this deep hydrogenation process. A CO2‐assisted green method was developed for the controllable synthesis of various bimetallic and monometallic catalysts. The PdNi/SBA‐15 catalysts with various Pd/Ni ratios exhibited a volcano‐like trend between BHMTHF yield and Pd/Ni ratio. Among all catalysts tested, Pd2Ni1/SBA‐15 achieved the best performance, converting 99.0 % of HMF to BHMTHF with 96.0 % selectivity, surpassing previously reported catalysts. Additionally, the Pd2Ni1/SBA‐15 catalyst maintained excellent stability even after five recycling runs. Catalyst characterizations (e. g., HAADF‐STEM) and density functional theory (DFT) calculations confirmed the successful formation of the alloy structure with electron transfer between Ni and Pd, which accounts for the remarkable performance and stability of the catalyst. This work paves the way for developing highly selective and stable alloy catalysts for biomass valorization. [ABSTRACT FROM AUTHOR]

The [c2]daisy chain rotaxane is an attractive interlocked molecule for the development of functional materials because of its unique mechanical properties that respond to various external stimuli, resulting in extension and contraction motions along the molecular axis. The synthesis of several ‘impossible’ [2]rotaxanes that do not exhibit obvious binding motifs between their axle and wheel moieties has been achieved through further chemical modification of their axle moieties within pre‐prepared [2]rotaxanes. However, no ‘impossible’ [c2]daisy chain rotaxane has been synthesized using similar strategies until now. In this study, we investigated the hydrogenation of diarylacetylene moieties within a permethylated α‐cyclodextrin (PM α‐CD)‐based [c2]daisy chain rotaxane using Pd/C or Pd/CaCO3 under hydrogen. A new [c2]daisy chain rotaxane featuring two diarylethane moieties was successfully synthesized through the simultaneous full hydrogenation of the insulated diarylacetylene moieties under optimized conditions. The new rotaxane is classified as an ‘impossible’ [c2]daisy chain rotaxane due to the lack of obvious binding motifs between diarylethane and the PM α‐CD. This work demonstrates for the first time that the insulated axle moieties of [c2]daisy chain rotaxanes can undergo novel chemical modifications using a synthetic strategy employing transition metal‐catalyzed hydrogenation, which can potentially advance the development of nanoarchitectures with functional interlocked molecules. [ABSTRACT FROM AUTHOR]

Cu/SiO2 catalysts are widely applied to the hydrogenation of dimethyl oxalate and ethylene carbonate to the corresponding ethylene glycol and methanol simultaneously, whereas ethylene glycol and methanol are important bulk commodities and raw materials for the production of oxygen‐containing chemicals and fuels. However, Cu particles usually aggregate or sinter to deactivate and the ratio of surface Cu0/Cu+ species is also difficult to control under the reaction conditions, so that the catalyst activity and stability is still a big challenge. It was found that modification of Cu‐based catalysts with certain organic compound inhibited the agglomeration of Cu particles, regulated the ratio of surface Cu0/Cu+ species, and even generated carbon layers to protect the Cu particles, which definitely improved the stability of the catalyst along with the enhanced catalytic performance. In this review, recent developments in ester hydrogenation over organic compound‐modified Cu/SiO2 catalysts were summarized and the issues to be further clarified are discussed as well. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of alkynes to alkenes using a low‐cost non‐noble metal catalyst is urgently desirable but challenging because of their over‐hydrogenation to undesired alkanes. Herein, a series of hierarchical N‐doped carbon nanosheets anchored bimetallic oxides were successfully fabricated. The resultant composite catalysts had advantages associated with not only two‐dimensionality (2D) nanosheets with highly active sites and fast mass transfer, but also bimetallic oxides that dissociate and transfer hydrogen with the assistance of the oxygen vacancies. Furthermore, the bimetallic oxides combined with the advantages of high activity of Ni and the selectivity regulation of Co. Benefiting from these advantages, the catalytic performance of CoNiO2−ZnCo2O4/NC NSs can reach nearly full conversion with 92 % selectivity at moderate reaction conditions and can keep excellent selectivity even prolonging the reaction time to 12 h, outperforming CoNiO2−ZnCo2O4/NC NPs, CoO−ZnCo2O4/NC NSs, and the commercial Lindlar catalysts, which demonstrate the huge potential for selective hydrogenation applications. [ABSTRACT FROM AUTHOR]

Biomass‐derived feedstocks play a vital role in sustainable economies for renewable energy, waste management, energy security, and commercial prospects. This study focused on promoting the ring hydrogenation of furfural (FAL) into tetrahydrofurfuryl alcohol (THFA) in an aqueous solution using a potential Ni−Re‐supported hydrotalcite‐derived MgAl catalyst at different Ni : Re molar ratios. Structural analyses, such as an in situ time‐resolved X‐ray absorption near edge structure, under H2 reduction elucidated the simultaneous transformation of Re6+ and Re7+ to Re0 with the remaining highly stable Ni2+. The construction of Ni−Re on hydrotalcite‐derived MgAl catalyst resulted in the alleviated H2 reduction behavior, facilitated H2 adsorption and desorption processes, and suitable catalyst acidity detected by H2 temperature‐programmed reduction, and H2 and NH3 temperature‐programmed desorption experiments, respectively. Under optimized conditions, a maximum THFA yield of 78 % with a complete FAL conversion was attained using Ni1Re0.16/MgO−Al2O3 catalyst at a reaction temperature of 140 °C, H2 pressure of 20 bar, catalyst loading of 20 %, and reaction time of 2 h in a H2O system. Isotopic deuterium (D2O) labeling revealed that D substitution was notably pronounced through isotopic exchange between the D atom from D2O and H atom in FAL during its hydrogenation to THFA. [ABSTRACT FROM AUTHOR]

A series of bis‐cyclometalated chiral‐at‐metal iridium(III) complexes containing a coordinated secondary phosphine oxide (SPO) have been synthesized and evaluated as catalysts in the asymmetric transfer hydrogenation (ATH) of acetophenone. The catalytic results show that SPO ligands have a non‐innocent role in activating the catalytic process. Additionally, it has been observed that for the same chiral descriptor (Δ‐at‐Ir or Λ‐at‐Ir), the major enantiomer formed depends on the nature of the cyclometalating ligand. These enantiodivergent results contravene the general assumption that the chiral‐at‐metal core's chirality dictates the sense of the chiral induction. A combined analysis of the main structural features of the catalysts deduced from XRD structures and in situ NMR spectroscopy allowed us to propose a simplified catalytic cycle and a working hypothesis to explain the observed enantioselectivities. [ABSTRACT FROM AUTHOR]

In this study, nickel (Ni) nanoparticles were successfully synthesised using two methods: the hot‐injection method and a room temperature colloidal synthesis using dioctyl tartrate as a capping agent. Each approach yielded Ni nanoparticles with unique morphological and electronic properties. The distinct characteristics of these Ni nanoparticles make them promising candidates for unravelling structure/activity relationships, a crucial aspect in developing catalysts with enhanced selectivity. Furthermore, Ni nanoparticles synthesized via these methods were supported on both silica and activated charcoal, with variations in Ni loadings. We explored the impact of nanostructural characteristic of the Ni NPs as well as support effects on the selective hydrogenation of furfural. Using temperature programmed reduction, advanced X‐ray absorption spectroscopy, and atom‐resolved electron microscopy techniques, we established comprehensive structure‐function relationships. Herein, we demonstrate that using a dioctyl tartrate route, foam‐like Ni nanostructures are obtained, yielding higher selectivity towards selective hydrogenation than commercial Ni/Al2O3 and a suppression of the acid‐base catalysed acetalization and etherification reactions. Furthermore, conversions similar to commercial Ni/Al2O3 are achieved using a lower Ni loading. These insights provide valuable guidance for the design of enhanced materials, contributing to the optimization of catalyst performance in selective hydrogenation processes. This research marks a significant step toward the development of more efficient and sustainable catalytic processes. [ABSTRACT FROM AUTHOR]