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Uniform and minuscule Ru particles confined in NaY zeolite (Ru@NaY) are prepared via a simple in situ synthesis technique. Transmission electron microscopy studies indicate that the Ru particles are encapsulated within the micropores of NaY zeolite and form a uniform size of 1.5–3.5 nm. Thanks to the effective confinement of Ru particles within the NaY zeolite, as well as the high concentration of B-5 sites and basic sites, the prepared Ru@NaY catalysts show excellent NH 3 decomposition activity and highly efficient H 2 formation. Notably, the 0.1Ru@NaY catalyst achieves a 92.7% NH 3 conversion and a H 2 formation rate of 690 mmol min−1·g Ru −1 at 500 °C and GHSV = 9000 mLNH 3 ·g cat −1·h−1 and shows outstanding stability throughout a 95-h lifetime test. The encapsulation synthesis of Ru clusters in zeolites endows the catalysts with exceptional catalytic activities and excellent stability, thus providing new prospects for the production of H 2 from NH 3 decomposition. [Display omitted] • Ru particles confined within NaY zeolite were prepared via hydrothermal synthesis. • Ru nanoparticles are uniformly sized, highly distributed, and thermally stable. • Ru@NaY catalysts showed high activity and stability for ammonia decomposition. • High level B-5 sites and basic sites accounts for the superior activity of Ru@NaY. [ABSTRACT FROM AUTHOR]

The Z-alkene geometry is prevalent in various chemical compounds, including numerous building blocks, fine chemicals, and natural products. Unfortunately, established Mo, W, and Ru Z-selective catalysts lose their selectivity at high temperatures required for industrial processes like reactive distillation, which limits their synthetic applications. To address this issue, we develop a catalyst capable of providing Z-alkenes with high selectivity under harsh conditions. Our research reveals a dithiolate ligand that, stabilised by resonance, delivers high selectivity at temperatures up to 150 °C in concentrated mixtures. This distinguishes the dithioquinoxaline complex from existing Z-selective catalysts. Notably, this trait does not compromise the new catalyst's usability under classical conditions, matching the activity of known stereoretentive catalysts. Density Functional Theory calculations were employed to understand the reaction mechanism and selectivity, and to investigate the poisoning that the catalyst may undergo and how it competes with catalytic activity. Furthermore, the quinoxaline-based catalyst enables the valorisation of bio-sourced alkene feedstocks and the production of agricultural sex pheromones for pest control. The Z-alkene geometry is prevalent in various chemical compounds, but established Mo, W, and Ru Z-selective catalysts lose their selectivity at high temperatures, which limits their synthetic applications. Here, the authors develop a catalyst capable of providing Z-alkenes with high selectivity under harsh conditions. [ABSTRACT FROM AUTHOR]

In this work, ruthenium-based catalysts were synthesized via polyol reduction method with different metal oxides as support and caesium as promoter. The samples were characterized through XRD, ICP-OES, nitrogen physisorption and XPS. Then, the catalysts were tested for ammonia synthesis in the range of temperatures 548–673 K and pressures 1–5 MPa. The synthesized catalysts allowed an ammonia production rate approximately four times higher compared with the performances of similar catalytic formulations in literature (tested at same conditions). The best performance were achieved with the Cs–Ru/CeO 2 (1% wt Cs, 5% wt Ru), reaching an ammonia production of nearly 73 mmol h−1∙g cat −1 at 673 K and 5 MPa. As showed by the XPS analysis, the increased Ce3+/Ce4+ ratio led to an enhancement of oxygen vacancies, which favoured the dissociative adsorption of nitrogen, that is the limiting step in the ammonia synthesis reaction. Such high catalytic activity can be ascribed to the beneficial effect of the polyol reduction method for the maximization of the exposure of active sites. [Display omitted] • Ru-catalysts were synthesized via polyol reduction and tested for NH 3 production. • Cs–Ru/CeO 2 enabled a NH 3 production rate of 43 mmol h−1∙g cat −1 at 673 K and 1 MPa. • Increased Ce3+/Ce4+ ratio enhanced oxygen vacancies favouring N 2 adsorption. [ABSTRACT FROM AUTHOR]

Exploring efficient and economical electrocatalysts to replace noble metal electrocatalysts has become a major research focus nowadays. In this paper, Ru-doped Co nanoparticles loaded on carbon nanosheet (CNS) in-situ grown on carbon nanofibers (Ru–Co@CNS/CNFs) were constructed as a self-supporting working electrode for high-efficiency hydrogen evolution. The prepared Ru–Co@CNS/CNFs possessed excellent catalytic activity with only 78 mV overpotential at 10 mA cm−2 current density and good stability with only 102 mV voltage attenuation at 100 mA cm−2 current density for 100 h continuous operation. The excellent catalytic performance could be attributed to the unique microstructure of the nanosheets in-situ grown on the nanofibers, it resulted in a higher Co surface density of 1.28 mg cm−2, indicating more loading of metal to improve catalytic activity of HER, and the formed Ru-doped Co nanoparticles could be evenly distributed on the carbon nanosheets to prevent the aggregation of nanoparticles, which could expose more active sites. Additionally, the density functional theory (DFT) calculations revealed Ru doping could accelerate the dissociation of water, optimize the adsorption energy of hydrogen intermediates and improve the kinetics of the HER reaction. This work provides a new approach to reduce the use of noble metals while improving the catalytic performance of catalysts. [Display omitted] • Microstructure of nanosheets in-situ grown on nanofiber was synthesized by electrospinning and immersion method. • The unique microstructure loaded more metal content and exposed more active site. • Ru doping accelerated water dissociation, optimized ΔG H* , and improved HER reaction kinetics. • The Ru–Co@CNS/CNFs catalyst possessed excellent catalytic performance (ƞ 10 = 78 mV, ƞ 100 = 228 mV). • It showed exceptional stability after testing for 100 h at the density of 100 mA cm−2. [ABSTRACT FROM AUTHOR]

The catalytic activity of a Ru complex 1, bearing a fused π‐conjugated imidazo[1,2–a][1,8]naphthyridine‐based mesoionic carbene (MIC) ligand, is examined for the oxidation of primary amines. Complex 1 affords nitrile or imine depending on the nature of the terminal oxidants and solvents used in the reactions. Primary amines are converted to nitriles using NaIO4 in EtOAc/H2O mixture, whereas imines are obtained under O2 balloon pressure in toluene. A variety of nitriles and imines are accessed with high yields and selectivity. A set of control experiments, reaction profiles, and kinetic studies are undertaken to disclose the mechanistic details for nitrile and imine formation. The catalytic reactions illustrate a subtle dependency on the choice of oxidants and solvents in the oxidation of primary amines. [ABSTRACT FROM AUTHOR]

Depletion of oil and gas resources is a major concern for researchers and the global community. Researchers are trying to develop a way to overcome these issues using the Fischer-Tropsch synthesis (FTS) process. The FTS reaction converts a mixture of hydrogen and carbon monoxide gases into a liquid fuel. The reactions are performed in the reactor and in the presence of a catalyst. A series of catalysts, such as iron, cobalt, nickel, and ruthenium, have been used for the FTS process. In iron-based catalysts, the Fe5C phase is the active phase that produces C5+ hydrocarbons. At higher conversion rates, the presence of water in the products is a problem for cobalt catalysts because it can trigger catalyst deactivation mechanisms. Ni-based catalysts play key roles as base catalysts, promoters, and photothermal catalysts in FTS reactions to produce different useful hydrocarbons. Ruthenium catalysts offer not only high activity but also selectivity toward long-chain hydrocarbons. Moreover, depending on the Ru particle size and interaction with the oxide support, the catalyst properties can be tuned to enhance the catalytic activity during FTS. The detailed reaction pathways based on catalyst properties are explained in this article. This review article describes the issues and challenges associated with catalysts used for the FTS process. [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]

Investigating clean and sustainable hydrogen generation from water splitting requires cost‐effective and highly efficient electrocatalysts for the hydrogen evolution reaction (HER). Ruthenium (Ru)‐based heterostructure catalysts have emerged as promising alternatives to precious Pt, offering significant potential to overcome current bottlenecks. Recent advancements in Ru‐based heterostructure catalysts have focused on achieving a balance between catalytic activity and stability. An overview of these developments provides insights into catalytic mechanisms and facilitates the development of novel catalysts. This review begins with an exploration of the enhanced activity of heterostructure catalysts, followed by a critical summary of synthetic strategies employed to fabricate these catalysts and their catalytic performances for HER. Attention is then directed to experimental endeavors aimed at enhancing the HER performance of Ru‐based heterostructure catalysts. Finally, the opportunities and challenges in developing heterostructure catalysts from the perspectives of material design and synthesis are discussed. Through these discussions, a comprehensive understanding of Ru‐based heterostructure catalysts and inspiring future research directions is the aim to provide. [ABSTRACT FROM AUTHOR]

A mechanochemical‐enabled Ru‐catalyzed regioselective synthesis of 3,4‐isoxazoles and 3,4,5‐isoxazoles from terminal and internal alkynes and hydroxyimidoyl chlorides is reported. This solid‐state and solvent‐free approach carefully examines the impact of the milling conditions on regiocontrol in 1,3‐dipolar cycloadditions using mechanochemical means. The study reveals that milling frequency, jar material, and the choice of liquid additive for liquid‐assisted grinding (LAG) significantly influence the catalytic activity of the Ru catalyst. Transmission electron microscope (TEM) analysis confirms the crucial role of coordinating liquid additives such as acetone and cyclopentyl methyl ether (CPME) in stabilizing and reducing the size of the in‐situ formed Ru nanoparticles, which is essential for catalytic activity. The applicability of this protocol is further demonstrated through the synthesis of a library of 3,4‐ and 3,4,5‐isoxazoles from a wide range of terminal and internal alkynes with varying physical states and electronic properties that highlights the potential of this method for the synthesis of more complex target molecules. [ABSTRACT FROM AUTHOR]

A series of M/NiCo-Ferrite (M: Pt, Pd, Ru, and Rh) nanoparticles were successfully synthesized, through a facile sol–gel auto-combustion followed by impregnation-reduction approach, as a catalyst for hydrogen generation from hydrolysis of NaBH4. All synthesized samples were characterized by XRD, N2 adsorption–desorption method, ICP-OES, FE-SEM, and EDX analysis. Compared to the other samples, it was observed that the Rh/NiCo-Ferrite sample exhibited higher particle distribution and surface area. To evaluate the hydrogen generation rate, the hydrolysis was carried out at a temperature of 35 °C, with an aqueous solution containing 5 wt.% NaBH4 and 3 wt.% NaOH. The experimental findings indicate that the Rh/NiCo-Ferrite sample exhibited a superior rate of hydrogen generation, with an average value of 11,667 mL/min.gcat, compared to the other samples studied. Enhanced catalytic properties may be responsible for its high activity. In addition, the activation energy of hydrolysis of sodium borohydride over the Rh/NiCo-Ferrite sample was 54.5 kJ/mol which is lower than the activation energy of many Ferrite-based catalysts. Moreover, the re-usability test of the Rh/NiCo-Ferrite sample denoted a decline in the catalytic activity after 4 recycling experiments due to the alterations in morphology and the reduction in the quantity of active phase. [ABSTRACT FROM AUTHOR]

Porous carbon supported metal catalyst with embedded structure has witnessed the success in enhancing catalyst stability; however, the development of a simple yet efficient strategy to fabricate catalyst with controllable embedding degree is still a great challenge. Herein, we report a facile impregnation-coating-pyrolysis (ICP) strategy to fabricate ultrafine Ru nanoparticles embedded into N-doped porous carbon nanosheets (Ru@CN). Both the dispersion and exposure degree of Ru nanoparticles in Ru@CN catalyst could be efficient controlled through regulating the coating time of carbon precursors. As expected, the obtained Ru@CN catalyst exhibited an acid resistance for the hydrogenation of levulinic acid in an aqueous phase. Specifically, the spent Ru@CN catalyst shows a significant enhancement in catalytic activity compared with fresh one because the fact that part of Ru active sites confined inside carbon support could be liberated during the reaction process. We anticipate that this ICP strategy may provide a new approach to fabricate the embedded catalyst with high hydrothermal stability. [ABSTRACT FROM AUTHOR]

Reaction of a sterically demanding iminophosphorano-phosphine, Ph2PCH2Ph2P＝NAr* (here onwards referred to as PCPNAr*; Ar* = 2,6-dibenzhydryl-4-methylphenyl), (1) with [Ru(η6-p-cymene)Cl2]2 yielded three different types of complex, [RuCl2{(η6-p-cymene)(PCPNAr*)-κ1-P}] (2), [RuCl{(P(O)CPNAr*)(κ2-N,C)(C-η6-arene)}] (3) and [RuCl{(POCP＝NAr*)(κ2-N,C-o)(C-η6-arene)}] (4), depending on the reaction conditions via CH activation, tethered η6-arene coordination, ortho-metallation or P＝N bond cleavage/rearrangement reactions. Interestingly, a similar reaction in CH3CN in the presence of AgBF4 resulted in the insertion of CH3CN into the P＝N bond to form a novel metallacycle [Ru(NCMe)3{(PC2P＝N(CH3)C＝NAr*)-κ3-N,N,P}][BF4]2 (5) containing 4- and 5-membered rings via an aza-Wittig type reaction. Complex 4 showed very good catalytic activity in the transfer hydrogenation of carbonyl compounds. [ABSTRACT FROM AUTHOR]

Developing high‐performance aviation fuel is highly desired for the rapid development of supersonic aircraft. Herein, selective deep hydrogenation of polycyclic aromatics to a high‐density fuel is developed over a Ru‐based catalyst. The influences of strong Ru‐support interaction on tailoring the reaction pathways of acenaphthene hydrogenation were investigated using different oxide supports (SiO2, CeO2, TiO2). Ru/CeO2 and Ru/TiO2 with strong SMSI possess abundant electron‐deficient Ruδ+ species which exhibit a good ability to promote H2 dissociation and increase the isomerization rate of saturated aromatic compounds. Due to the enhanced adsorption of aromatic molecules, Ru/CeO2 (1.30 μmol min−1 g−1) exhibits superior catalytic activity in comparison to Ru/TiO2 (1.25 μmol min−1 g−1) during acenaphthene hydrosaturation, while Ru/TiO2 exhibits the highest isomerization reaction rate (7.60×10−2 μmol min−1 g−1) because of its excellent hydrogen spillover ability and high content of Ruδ+ species. The best catalytic activity with 96 % selectivity of ccc‐perhydroacenaphthene was achieved on Ru/TiO2, and an isomerization mechanism of perhydroacenaphthene isomers was proposed. [ABSTRACT FROM AUTHOR]

In this work, Ru nanoparticles doped with Mo on reduced graphene oxide (RuMo/rGO) are prepared through synchronous reduction of RuCl3, MoCl5, and graphene oxide. The compositions, morphologies, and structures of the as-prepared RuMo/rGO composites are fully characterized. Their catalytic properties in oxidative cleavage of β-O-4 linkages in lignin model compounds and lignin are explored. It is illustrated that with O2 as the oxidant RuMo/rGO shows overall better catalytic performance in the oxidative cleavage of β-O-4 linkages than the catalysts, such as Ru/rGO and RuCo/rGO, reported in our previous work. The catalytic mechanism is elaborated through experiments and density functional theory (DFT) calculation. Pronouncedly, we show that the as-doped Mo can effectively boost the molecular oxygen activation process and the adsorption of β-O-4 model compounds on the Ru nanoparticle surface on rGO, and thus enhance the catalytic activity. It is demonstrated meanwhile that RuMo/rGO can catalyze the depolymerization of organosolv birch lignin yielding 17.1% aromatic compounds under relatively mild conditions (100 °C, 0.3 MPa O2, 12 h, pH = 12). [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) has higher energy barrier and slower kinetics, which limits the efficiency of electrocatalytic water splitting. Developing efficient catalysts is of great significance for improving oxygen evolution performance. Therefore, we developed a low-dose ruthenium-doped copper-nickel bimetallic organic framework self-supported electrode (Ru x CuNi-MOF/CF). The prepared Ru 0·004 CuNi-MOF/CF has excellent electrocatalytic activity and stability. At the current density of 10 mA cm−2, the overpotential is only 203 mV in 1 M KOH electrolyte, and it can work continuously and stably for 100 h. The Tafel slope of Ru 0·004 CuNi-MOF/CF is 57.01 mV dec−1. The excellent electrocatalyst performance is attributed to the following three points: (1) The self-supporting material does not need adhesives to avoid the inhibition of the conductive ability of the catalyst. (2) The Cu2+/Ni2+ lattice site is replaced by Ruδ+, and the electron rearrangement improves the conductivity and catalytic activity of the material. (3) The presence of zero-valence ruthenium nanoparticles can further provide more active sites and improve the electrochemical reaction rate. This work provides new insights into fabricating ruthenium-doped bimetallic organic framework self-supported electrode for the study of oxygen evolution performance. • Ingenious use of substrate in situ conversion to provide part of the metal source, reduce the cost of the experiment. • The Ru 0·004 CuNi-MOF/CF exhibits excellent durability after 100 h of continuous operation. • The electronic structure is regulated by Ru0/Ruδ+ to improve the electrochemical performance. [ABSTRACT FROM AUTHOR]

Molybdenum‐based efficient and broadly applicable catalytic system is presented for the dehydrogenative coupling of γ‐/β‐amino alcohols with ketones. In particular, complex Mo(CO)6 in combination with Xantphos and t‐BuOK as base provides direct synthesis of structurally diverse quinoline, pyridine, and pyrrole compounds (total 55 examples) with isolated yields up to 92%. Low catalyst loading, cost‐effective, and high catalytic activities with high tolerance to stand with diverse functional groups are additional features of these molybdenum catalysts exhibiting high efficacy to replace the precious metal catalysts such as ruthenium and iridium. Furthermore, the DFT and experimental studies were explored for the reaction mechanism which can assist in broadening the scope of the molybdenum catalysts for different transformation reactions. [ABSTRACT FROM AUTHOR]

Development of highly active and stable catalysts for production of COx-free hydrogen from ammonia is crucial for the use of ammonia as hydrogen carrier. Herein, Ru nanoparticles (NPs) on Nd2O3 (Ru/Nd2O3) was prepared by different methods and investigated for NH3 decomposition reaction. The dependence of the catalytic activity of Ru NPs on the Nd2O3 on the interaction between Ru NPs and Nd2O3 support was investigated in detail. The Ru/Nd2O3 obtained from precipitation method exhibits a high hydrogen formation rate of 1548 mmol gcat−1 h−1 at 450 °C, which is high than that of the Ru/Nd2O3 analogue from milling method and comparable with many efficient oxides supported Ru catalysts reported previously. As revealed by various characterization techniques, the high activity of Ru/Nd2O3 obtained from precipitation method can be attributed to the enhanced interaction between Ru NPs and Nd2O3. The Ru NPs in Ru/Nd2O3 analogue with enhanced the metal-support interaction can modulate electronic structure and facilitate the activation and decomposition of NH3. Therefore, Ru/Nd2O3 obtained from precipitation method exhibited significantly improved activity and intrinsic activity for NH3 decomposition. This study provides promise for the design of efficient Ru/Nd2O3 catalyst for NH3 decomposition reaction by tuning the metal–support interaction of catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Ru/Ni 3 Se 4 /Ni(OH) 2 /NF catalyst was synthesised via two-step hydrothermal method. • Spontaneous reconfiguration of electrons occurs at the heterointerface between Ru and Ni 3 Se 4 /Ni(OH) 2. • Ni 3 Se 4 /Ni(OH) 2 heterojunction facilitates stable catalysis of Ru nanoparticles. • Ru/Ni 3 Se 4 /Ni(OH) 2 /NF catalyst exhibit superior HER/OER activity and strong stability. Properly design and manufacture of bifunctional electrocatalysts with superb performance and endurance are crucial for overall water splitting. The interfacial engineering strategy is acknowledged as a promising approach to enhance catalytic performance of overall water splitting catalysts. Herein, the Ru nanoparticles modified Ni 3 Se 4 /Ni(OH) 2 heterostructured nanosheets catalyst was constructed using a simple two-step hydrothermal process. The experimental results demonstrate that the abundant heterointerfaces between Ru and Ni 3 Se 4 /Ni(OH) 2 can increase the number of active sites and effectively regulate the electronic structure, greatly accelerating the kinetics of the hydrogen evolution reaction (HER)/oxygen evolution reaction (OER). As a result, the Ru/Ni 3 Se 4 /Ni(OH) 2 /NF catalyst exhibits the low overpotential of 102.8 mV and 334.5 mV at 100 mA cm−2 for HER and OER in alkaline medium, respectively. Furthermore, a two-electrode system composed of the Ru/Ni 3 Se 4 /Ni(OH) 2 /NF requires a battery voltage of just 1.51 V at 10 mA cm−2 and remains stable for 200 h at 500 mA cm−2. This work provides an effective strategy for constructing Ru-based heterostructured catalysts with excellent catalytic activity. [ABSTRACT FROM AUTHOR]

Oxides have traditionally been considered inert in hydrogen evolution reaction due to their strong adsorption of hydrogen. Here, we successfully prepared a novel RuCoWOx-400 catalyst by strategically adjusting the calcination temperature to manipulate the growth of oxide heterointerfaces. The characterization techniques reveal that RuCoWOx-400 is a porous structure and contains multiple heterogeneous interfaces to enhance catalytic activity. Additionally, the as-synthesized RuCoWOx-400 exhibits low overpotential of 93 mV at 10 mA cm−2 coupled with small Tafel slope of 37.22 mV dec−1 in 1 M KOH. Remarkably, the electrochemical performance of RuCoWOx-400 remains stable for up to 50 h. Moreover, the adsorption and desorption of water at Co, W, and Ru sites coordinate the hydrogen evolution reaction, highlighting the unique role of these elements in enhancing catalytic activity. This study underscores the potential of oxide materials in hydrogen evolution reaction, paving the way for further exploration and optimization in this field. [Display omitted] • Simple temperature-controlled calcination constructs heterogeneous RuCoWOx-400. • The synergistic effect of various metal oxides improves the performance of HER. • Heterogeneous interfaces optimize the electronic structure between metal oxides. • Porous and heterogeneous surface increased active area and active site. [ABSTRACT FROM AUTHOR]

In recent years, single‐atom catalysts (SACs) have become the most active part of the catalytic field due to their excellent catalytic activity. Among them, Ru SACs exhibit excellent performance in many catalytic applications due to their high atomic utilization efficiency, catalytic activity and selectivity, and relatively low cost. In order to understand the structure–performance relationship and potential catalytic mechanism of Ru SACs, this review summarizes the research progress of Ru SACs in the fields of electrocatalytic water splitting, fuel cells, nitrogen reduction, and nitrate reduction in recent years. The catalytic process of Ru single atom in different synthesis methods and modification strategies is summarized. Finally, some opportunities and challenges for the future development of Ru SACs are prospected. [ABSTRACT FROM AUTHOR]

A potassium (K)-promoted Ru-based siliceous molecular sieve catalyst, K-nRu-MCM-41, was successfully synthesized via a hydrothermal method. The combined analysis of XRD, FT-IR and XPS data revealed that Ru exists in the framework of the molecular sieves as RuO2 species, leading to structural alterations. SEM and TEM images demonstrated that Ru doping disrupts the morphology of the molecular sieves, while K addition effectively preserves the original morphology and further enhances particle dispersion. The ammonia decomposition performance test indicated that K promotes the activity of the molecular sieve catalysts. At 450 °C and 12 000 mL gcat−1 h−1, K-4Ru-MCM-41 achieved 82.7% ammonia conversion and 253.6 mmol gRu−1 min−1 hydrogen production, respectively, which was a 7.6% increase in ammonia conversion compared with 4Ru-MCM-41. Furthermore, the K-4Ru-MCM-41 catalyst exhibited excellent reusability, maintaining its stable catalytic activity performance after 30 h. [ABSTRACT FROM AUTHOR]

[Display omitted] A series of novel ruthenium(ii) complexes with nitron-type N-heterocyclic carbene ligands containing chelating (N -arylcarbamoyl)methyl or carboxymethyl groups have been synthesized. Their evaluation as precatalysts in the hydrogenation of ketones has revealed that the complex containing three N -mesityl groups (one on the carbamoyl- methyl moiety and two on the triazole moiety) is the most efficient one. [ABSTRACT FROM AUTHOR]

This work focuses on the study of biodiesel production from commercial rapeseed oil and methanol via transesterification reactions on monometallic copper and bimetallic copper–noble metal (platinum, ruthenium) catalysts supported on BEA zeolite. The catalysts were prepared by wet impregnation method on the hydrogen form of BEA zeolite. As part of the study, the physicochemical and catalytic properties of the prepared catalytic materials were determined. The catalytic activity tests were carried out in the transesterification reaction over prepared catalysts at 220 °C for 2 h in an autoclave. The physicochemical properties of the obtained catalysts were investigated by X-ray diffraction (XRD), specific surface area and porosity (BET), a scanning electron microscope equipped with an energy dispersive spectrometer (SEM–EDS) and temperature-programmed desorption of ammonia (TPD-NH3) method. The results of the catalytic activity showed the promotional effect of the noble metal on the TG conversion and FAME efficiency of copper catalysts in the biodiesel production process. The most active catalyst turned out to be the calcined 5%Cu–1%Ru/BEA catalyst, which showed the highest TG conversion of 85.7% and the second highest FAME efficiency of 58.4%. The high activity of this system is explained by its surface acidity and large specific surface area. [ABSTRACT FROM AUTHOR]

The Fe(OH) x -Ru/Ni(OH) 2 nanosheets array electrocatalysts are prepared by an acid etching assisted electrodeposition method, which shows outstanding catalytic activity with a low voltage of 1.649 V at 500 mA cm−2 for overall water splitting. [Display omitted] • Fe(OH)x-Ru/Ni(OH)2 nanosheets arrays were synthesized by a simple acid etching assisted electrodeposition method at room temperature. • Fe(OH)x-Ru/Ni(OH)2 nanosheets arrays exihibit an excellent activity to both HER and OER. • Fe(OH)x-Ru/Ni(OH)2 nanosheets arrays pair achieve 500 mA cm − 2 at 1.649 V. Developing highly active electrocatalysts for overall water splitting is of remarkable significance for industrial production of H 2. Herein, exceptionally active Fe(OH) x modified ultra-small Ru nanoparticles on Ni(OH) 2 nanosheets array (Fe(OH) x -Ru/Ni(OH) 2) for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are reported. The Fe(OH) x -Ru/Ni(OH) 2 nanosheets array prepared with Fe/Ru molar ratio of 5 only requires extremely low overpotentials of 61, 127 and 170 mV to reach current densities of 100, 500 and 800 mA cm−2 in 1 M KOH, respectively, exceeding Pt/C catalyst (75, 160 and 177 mV). Meanwhile, the Fe(OH) x /Ni(OH) 2 nanosheets array derived from Fe(OH) x -Ru/Ni(OH) 2 exhibits excellent OER activity. It gains current densities of 100, 500 and 800 mA cm−2 at considerably low overpotentials of 265, 285 and 296 mV, respectively, much lower than those of RuO 2 and most reported electrocatalysts. The introduction of Fe(OH) x significantly improves the HER activity of Ru nanoparticles by tunning the electronic structure and forming interfaces between Ru and Fe(OH) x. Dramatically, the integrated alkaline electrolyzer based on Fe(OH) x -Ru/Ni(OH) 2 and Fe(OH) x /Ni(OH) 2 nanosheets array pair just needs 1.649 V to yield a current density up to 500 mA cm−2, exceeding most reported water-splitting electrocatalysts. The strategy reported in this work can be facilely extended to prepare other similar Ru based materials and their derivatives with outstanding catalytic performance for water splitting. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel sulfates supported binary RuIrO x be synthesized. • A strong catalyst-support interaction between RuIrO x and BaSrSO 4. • The RuIrO x /BSS exhibits a high OER mass activity of only 324 mV overpotential at 1000 A/g Ru + Ir. • It shows outstanding CER activity and stability. Electrolysis for producing hydrogen powered by renewable electricity can be dramatically expanded by adapting different electrolytes (brine, seawater or pure water), which means the anode materials must stand up to complex electrolyte conditions. Here, a novel catalyst/support hybrid of binary Ru 3.5 Ir 1 O x supported by barium strontium sulfate (BaSrSO 4) was synthesized (RuIrO x /BSS) by exchanging the anion ligands of support. The as-synthesized RuIrO x /BSS exhibits compelling oxygen evolution (OER) and chlorine evolution (CER) performances, which affords to 10 mA cm−2 with only overpotential of 244 mV and 38 mV, respectively. The performed X-ray adsorption spectra clearly indicate the presence of an interface charge transfer effect, which results in the assignment of more electrons to the d orbitals of the Ru and Ir sites. The theoretical calculations demonstrated that the electronic structures of the catalytic active sites were modulated to give a lower overpotential, confirming the intrinsically high OER and CER catalytic activity. [ABSTRACT FROM AUTHOR]

The development of electrocatalysts capable of efficiently catalyzing the alkaline hydrogen evolution reaction (HER) is crucial for driving the advancement of sustainable energy. Herein, by altering the surface state of the support, we transformed the bulk W 5 N 4 into a porous structure and constructed a Ru/W 5 N 4 heterostructure. The transfer of electrons from Ru to W 5 N 4 can optimize the electronic structure of the catalyst, thereby effectively promoting electron transfer, accelerating reaction kinetics, and enhancing the activity of the catalyst. Furthermore, W 5 N 4 can serve as a protective shell to stabilize Ru0, which is regarded as the active center in HER. The resulting Ru/W 5 N 4 exhibits excellent HER activity, requiring only overpotentials of 43 and 156 mV to achieve current densities of −10 and −100 mA cm−2, respectively. This work provides valuable insights into the rational construction of heterostructures to optimize HER performance. • The Ru/W 5 N 4 /NF catalysts were synthesized by a conventional two-step method. • Electronic interaction between W 5 N 4 and Ru can enhance the catalytic activity. • Interface engineering is an effective method to regulate the interfacial charge. • The W 5 N 4 greatly enhances the hydrogen evolution efficiency of Ru in alkaline medium. [ABSTRACT FROM AUTHOR]

Hyperbranched polymer–supported ruthenium NPs were used for hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in water. The catalytic nanocomposite showed 99.9% LA conversion and 100% GVL selectivity under mild conditions and low Ru loading in batch reactor under H2. Ru NPs formed in situ during the hydrogenation of LA demonstrated the higher catalytic activity over pre-synthesized Ru NPs. Superior catalytic properties of Ru nanocomposites are attributed both to the formation of small Ru NPs and to the effect of pyridine containing polymer support, which provides a reliable dispersion of Ru species over support and at the same time due to weak alkalinity, promotes interaction with LA thereby facilitating catalytic reaction. The functional hyperbranched polymer contributes to high stability of supported Ru NPs which was demonstrated in six consecutive catalytic cycles. TEM, XPS, EDS, XRD were used to analyze the structure, NPs distribution, and oxidation state of Ru catalysts before and after catalytic reactions. [ABSTRACT FROM AUTHOR]

To meet the increasing demand for small-scale NH3 production, catalysts that work under milder conditions than those of the Haber–Bosch process are essential. In this study, Ru clusters and nanoparticles were impregnated on five different CeO2 supports to prepare Ru/CeO2 catalysts for NH3 synthesis at 400 °C and 0.1 MPa. The basicity of the CeO2 support and Ru particle size significantly influenced the catalytic activity. The catalytic activity increased with decreasing Ru particle size, reaching the maximum of ~ 200 mmol gRu−1 h−1 at ~ 1 nm, which is ascribed to a high proportion of unique active sites different from the B5-type sites. Our findings demonstrate that Ru cluster catalysts are advantageous over Ru nanoparticle catalysts for NH3 synthesis. [ABSTRACT FROM AUTHOR]

The introduction of heteroatoms into manganese dioxide (MnO2) is an effective method to adjust the active site of electrochemical water oxidation catalysis. Although many modification methods for MnO2 have been studied in electrocatalytic oxygen evolution reaction (OER), few studies have focused on the influence of regulating different crystal forms of MnO2 on catalytic activity. This article prepared four different crystal forms of MnO2 (α-MnO2, β-MnO2, γ-MnO2 and δ-MnO2), and systematically studied the catalytic performance of the catalyst (x-MnO2-Ru) prepared by adding Ru to α-MnO2, β-MnO2, γ-MnO2 and δ-MnO2 for OER. The results of linear sweep voltammetry and chronopotentiometry measurements show that the catalyst prepared by adding Ru to β-MnO2 (β-MnO2-Ru) has the best electrochemical performance. β-MnO2 -Ru shows a low overpotential (300 mV at 10 mA·cm-2) and outstanding catalytic activity with small degradation after 24 h operation. It is found that β-MnO2-Ru exhibits excellent electrocatalytic performance due to its abundance of Mn3+ and defect oxygen vacancies. [ABSTRACT FROM AUTHOR]

We report the development of Ru/Mg–Al oxide coated metal-structured catalysts with excellent heat and mass transfer characteristics for efficient clean H 2 production from ammonia decomposition. Ammonia is a promising carrier for the mass transport of hydrogen and facilitates the production of COx-free hydrogen by decomposing into nitrogen and hydrogen. Ru nanoparticles are uniformly dispersed on the Mg–Al oxide layer of the FeCralloy monoliths and foams via precipitation. The catalytic activities depend on the surface area and loading of the catalysts and the metal dispersion in the oxide layer. At temperatures <650 °C, and a gas hourly space velocity (GHSV) of 3,000 h−1, monolithic catalysts with a large surface area and evenly distributed active metals perform excellently. Foam catalysts with excellent heat transfer performance better at temperatures >650 °C and GHSV >6,000 h−1. Foam catalyst stability is verified for 100 h in a 20 Nm3/h high-purity hydrogen production system. [Display omitted] • COx-free H 2 production via NH 3 decomposition on Ru-coated metal-structured catalysts. • Nano-sized Ru uniformly dispersed in plate-like Mg–Al oxide layers by precipitation. • Amount of Ru in the structured catalyst was <∼1/10 of that in the pellet catalyst. • Foams performed better catalytically than monoliths at higher GHSV (6,000 h−1). • Foam catalyst stability was verified in a 20 Nm3/h-H 2 production system for 100 h. [ABSTRACT FROM AUTHOR]

Designing highly active and durable catalysts is considered to be crucial for enhancing hydrogen evolution reaction (HER) from water electrolysis. Although some studies indicate that anatase TiO 2 is a promising candidate for electrolytic hydrogen evolution reaction, the influence of different crystalline phases of TiO 2 on the supported Ru catalysts for electrocatalytic HER performance is rarely systematically explored. Herein, a series of Ru/TiO 2 -X (X = R (Rutile), A (Anatase), and P25) catalysts were prepared to investigate the influence of the rutile and anatase phases of TiO 2 on the catalytic activity of Ru catalysts in HER. The findings demonstrate that the HER activity is much affected by the variation of the titania structure, when other factors are kept constant. The 15Ru/TiO 2 -R-H 2 has superior HER performance with a small overpotential of 63 mV to achieve a current density of 10 mA cm−2 in acidic electrolyte and 99 mV in alkaline electrolyte compared to 15Ru/TiO 2 -A-H 2 and 15Ru/TiO 2 -P25-H 2. This might be attributed to the faster electron transfer and lower Fermi level caused by the oxygen vacancy (V O) and strong metal-support interaction (SMSI), along with the exposure of active sites afforded by the highly dispersed ruthenium nanoparticles on the rutile TiO 2. Our results indicate that the presence of rutile TiO 2 support alone is adequate to maintain Ru in its most active form and make it a more performing catalyst, compared to anatase titania and P25. • Ru is supported on different crystalline phase of TiO 2 for electrocatalytic HER. • Partial Ru is incorporated the lattice of TiO 2 -R with SMSI effect. • Highly dispersed Ru and rich V O promote electrocatalytic HER. • Electron transfer from V O and Ti to surface Ru is conducive to optimizing HER. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Realizing the hydrogen economy by water electrolysis is an attractive approach for hydrogen production, while the efficient and stable bifunctional catalysts under high current densities are the bottleneck that limits the half‐cell reactions of water splitting. Here, we propose an approach of hydrothermal and thermal annealing methods for robust MoO2/MoNi4@Ru/RuO2 heterogeneous cuboid array electrocatalyst with multiplying surface‐active sites by depositing a monolayer amount of Ru. Benefiting from abundant MoO2/MoNi4@Ru/RuO2 heterointerfaces, MoO2/MoNi4@Ru/RuO2 heterogeneous cuboid array electrocatalysts effectively drive the alkaline water splitting with superior hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances. The synthesized MoO2/MoNi4@Ru/RuO2 has high HER activity, which realizes the working overpotentials of 48 mV at 50 mA·cm–2, further achieving overpotentials of 230 mV for industry‐level 1000 mA·cm–2 in alkaline water electrolysis. Moreover, it also showed an enhanced OER activity than commercial RuO2 with a small overpotential of 280 mV at 200 mA·cm–2 in alkaline media. When building an electrolyzer with electrodes of (–)MoO2/MoNi4@Ru/RuO2IIMoO2/ MoNi4@Ru/RuO2 (+), a cell voltage of 1.63 V and 1.75 V is just required to support the current density of 200 mA·cm–2 and 500 mA·cm–2 in alkaline water electrolysis, much lower than that of the electrolyzer of (–)Pt/CIIRuO2(+). This work demonstrates that MoO2/MoNi4@Ru/RuO2 heterogeneous nanosheet arrays are promising candidates for industrial water electrolysis applications, providing a possibility for the exploration of water electrolysis with a large current density. [ABSTRACT FROM AUTHOR]

The use of CO 2 -rich natural gas as feedstock in DRM is an attractive route of carbon dioxide utilisation due to the compositional advantage of these particular resources. The optimal operating conditions would potentially improve the overall thermal efficiency of the DRM process, especially when the temperature is lower than 800 °C. This study reports a catalyst with the demonstrated high performance and high coke-resistance, developed from ruthenium modified ceria-zirconia. Coprecipitation and hydrothermal methods were adopted to prepare the ceria-zirconia supports, and then impregnated with a very small amount of Ru (0.10 wt%). The structure-catalytic activity relationship of the catalyst was further investigated in DRM. High conversions of CH 4 and CO 2 , i.e., 44.0% and 57.4%, respectively, were achieved by using 0.1Ru1CZ5U-180 at low temperature of 600 °C. A significant reduction in the onset reaction temperature was observed from temperature programmed reduction (TPR) and this observation was related to the increased number of exchangeable oxygens in the presence of Ru. Nitrogen adsorption-desorption results suggested that the specific surface area and the total pore volume also improved the exchange of oxygen between adsorbed carbon dioxide molecules and the crystal lattice. It is evident that the presence of ruthenium accelerated the oxygen spillover process on the surface of the catalyst, and facilitated the dynamics of the oxygen exchange between the adsorbed carbon dioxide molecules and the ceria-zirconia, which ultimately contributed to the observed increase in catalytic activity at temperatures below 800 °C. Most importantly, no detectable carbon deposits were formed over the entire experimental period when the ruthenium modified ceria-zirconia catalyst was used. • A trace amount of Ru (0.10 wt%) was used to promote ceria-zirconia. • 0.10 wt% Ru significantly increased its reducibility and oxygen exchange dynamics. • Synthesis method showed a performance difference at temperatures between 400 and 850 °C. • 44% of CH 4 and 57.4% CO 2 were converted at 600 °C by 0.1Ru1CZ5U-180. • No observable carbon formation was detected from hydrothermally prepared samples. [ABSTRACT FROM AUTHOR]

Nature uses reactive components embedded in biological membranes to perform light‐driven photosynthesis. Here, a model artificial photosynthetic system for light‐driven hydrogen (H2) evolution is reported. The system is based on liposomes where amphiphilic ruthenium trisbipyridine based photosensitizer (RuC9) and the H2 evolution reaction (HER) catalyst [Mo3S13]2− are embedded in biomimetic phospholipid membranes. When DMPC was used as the main lipid of these light‐active liposomes, increased catalytic activity (TONCAT ~200) was observed compared to purely aqueous conditions. Although all tested lipid matrixes, including DMPC, DOPG, DPPC and DOPG liposomes provided similar liposomal structures according to TEM analysis, only DMPC yielded high H2 amounts. In situ scanning electrochemical microscopy (SECM) measurements using Pd microsensors revealed an induction period of around 26 minutes prior to H2 evolution, indicating an activation mechanism which might be induced by the fluid‐gel phase transition of DMPC at room temperature. Stern‐Volmer‐type quenching studies revealed that electron transfer dynamics from the excited state photosensitizer are most efficient in the DMPC lipid environment giving insight for design of artificial photosynthetic systems using lipid bilayer membranes. [ABSTRACT FROM AUTHOR]

New 1,2-azolylamidino complexes fac-[RuCl(DMSO)3(NHC(R)az*-κ²N,N)]OTf [R = Me (2), Ph (3); az* = pz (pyrazolyl, a), indz (indazolyl, b)] are synthesized via chloride abstraction from their corresponding precursors cis,fac-[RuCl2(DMSO)3(az*H)] (1) after subsequent base-catalyzed coupling of the appropriate nitrile with the 1,2-azole previously coordinated. All the compounds are characterized by ¹H NMR, 13C NMR and IR spectroscopy. Those derived from MeCN are also characterized by X-ray diffraction. Electrochemical studies showed several reduction waves in the range of −1.5 to −3 V. The electrochemical behavior in CO2 media is consistent with CO2 electrocatalytic reduction. The catalytic activity expressed as [icat(CO2)/ip(Ar)] ranged from 1.7 to 3.7 for the 1,2-azolylamidino complexes at voltages of ca. −2.7 to −3 V vs. ferrocene/ferrocenium. Controlled potential electrolysis showed rapid decomposition of the Ru catalysts. Photocatalytic CO2 reduction experiments using compounds 1b, 2b and 3b carried out in a CO2-saturated MeCN/TEOA (4 : 1 v/v) solution containing a mixture of the catalyst and [Ru(bipy)3]2+ as the photosensitizer under continuous irradiation (light intensity of 150 mW cm−2 at 25 °C, λ > 300 nm) show that compounds 1b, 2b and 3b allowed CO2 reduction catalysis, producing CO and trace amounts of formate. The combined turnover number for the production of formate and CO is ca. 100 after 8 h and follows the order 1b < 2b ≈ 3b. [ABSTRACT FROM AUTHOR]

Chemical upcycling that catalyzes waste plastics back to high‐purity chemicals holds great promise in end‐of‐life plastics valorization. One of the main challenges in this process is the thermodynamic limitations imposed by the high intrinsic entropy of polymer chains, which makes their adsorption on catalysts unfavorable and the transition state unstable. Here, we overcome this challenge by inducing the catalytic reaction inside mesoporous channels, which possess a strong confined ability to polymer chains, allowing for stabilization of the transition state. This approach involves the synthesis of p‐Ru/SBA catalysts, in which Ru nanoparticles are uniformly distributed within the channels of an SBA‐15 support, using a precise impregnation method. The unique design of the p‐Ru/SBA catalyst has demonstrated significant improvements in catalytic performance for the conversion of polyethylene into high‐value liquid fuels, particularly diesel. The catalyst achieved a high solid conversion rate of 1106 g ⋅ gRu−1 ⋅ h−1 at 230 °C. Comparatively, this catalytic activity is 4.9 times higher than that of a control catalyst, Ru/SiO2, and 14.0 times higher than that of a commercial catalyst, Ru/C, at 240 °C. This remarkable catalytic activity opens up immense opportunities for the chemical upcycling of waste plastics. [ABSTRACT FROM AUTHOR]

A class of 2‐hydroxypyridine based ligands are explored to achieve enhanced catalytic activity for ortho‐C−H bond activation/arylation reaction over [(η6‐p‐cymene)RuCl2]2 catalyst in water. Extensive studies using a series of substituted 2‐hydroxypyridine based ligands (L1–L6) inferred that 5‐trifluoromethyl‐2‐hydroxypyridine (L6) exhibited favorable effects to enhance the catalytic activity of Ru(II) catalyst for ortho C−H bond arylation of 2‐phenylpyridine by 8 folds compared to those performed without ligands. The (η6‐p‐cymene)Ru – L6 system also exhibited enhanced catalytic activity for ortho C−H bond arylation of 2‐phenylpyridine using a variety of aryl halides. NMR and mass investigations inferred the presence of several ligand coordinated Ru(II) species, suggesting the involvement of these species in C−H bond activation reaction. Further in concurrence with the experimental findings, the density functional theory (DFT) calculations also evidenced the prominent role of 2‐hydroxypyridine based ligands in Ru(II) catalyzed C−H bond arylation of 2‐phenylpyridine with lower energy barrier for the C−H activation step. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) have emerged as crucial players in catalysis research, prompting extensive investigation and application. The precise control of metal atom nucleation and growth has garnered significant attention. In this study, we present a straightforward approach for preparing SACs utilizing a photocatalytic radical control strategy. Notably, we demonstrate for the first time that radicals generated during the photochemical process effectively hinder the aggregation of individual atoms. By leveraging the cooperative anchoring of nitrogen atoms and crystal lattice oxygen on the support, we successfully stabilize the single atom. Our Pd1/TiO2 catalysts exhibit remarkable catalytic activity and stability in the Suzuki–Miyaura cross‐coupling reaction, which was 43 times higher than Pd/C. Furthermore, we successfully depose Pd atoms onto various substrates, including TiO2, CeO2, and WO3. The photocatalytic radical control strategy can be extended to other single‐atom catalysts, such as Ir, Pt, Rh, and Ru, underscoring its broad applicability. [ABSTRACT FROM AUTHOR]

The effect of Al 2 O 3 , TiO 2 , ZrO 2 and Yttria-Stabilized Zirconia (YSZ) supports on the activity of the dry reforming of CH 4 towards syngas production was investigated for Rh and Ru catalysts. Ruthenium-based catalysts were found to generally be more active than Rh leading H 2 /CO ratios close to unity above 700 °C. Methane conversion turnover frequency (TOF) over Rh catalysts becomes optimum for Rh/YSZ followed by Rh/TiO 2 and Rh/ZrO 2 , and finally Rh/Al 2 O 3 , which exhibited the lowest activity. The performance order is different for Ru catalysts, with TOF being increased in the order Ru/Al 2 O 3

The widespread use of pyridine‐based PNP pincer ligands has inspired the concept of metal‐ligand cooperation (MLC), in which the reactivity at the deprotonated CH2 (or NH) arm of the ligand is proposed to play an important role. Several groups developed a family of PNP‐type pincer ligands with methylated arms which were initially introduced to test the effect of blocking MLC in catalysis, but eventually led to unexpected consequences such as stabilization of unusual oxidation states, beneficial catalytic activity, or selectivity. Analysis of the sterics imposed by introducing Me groups revealed that arm protection can be an efficient tool to control sterics around the metal as an alternative to phosphine substitution, leading to much greater steric hinderance above and below pincer's coordination plane. This Concept will describe several illustrative examples which contrast the reactivity of classical CH2/NH‐arm PNP pincers with their CMe2/NMe‐armed counterparts, in particular related to Ru‐catalyzed alcohol dehydrogenative coupling, Fe‐catalyzed hydrogenation, hydroboration, and alkyne semihydrogenation. [ABSTRACT FROM AUTHOR]

Exploring highly active and robust catalysts, which have low precious metal content, to boost the kinetically sluggish oxygen evolution reaction (OER) is a key concern for hydrogen production via proton exchange membrane water electrolysis (PEMWE). Here, rational engineering of the morphology and the local geometric ligand environment of Ir and Ru catalysts are presented by using defect‐rich, lanthanum‐ and lithium‐doped Co3O4 nanofiber (LLCF) as substrate that promotes the electrocatalytic OER. Two catalysts, IrCoOx@LLCF and RuCoOx@LLCF, achieve mass activities of 1013.5 A gIr−1 and 1911.4 A gRu−1 in 0.1 m HClO4 at 300 mV overpotential, respectively, which are 26 and 50 times higher than that of commercial IrO2 and RuO2. Operando X‐ray absorption spectroscopy unveils the reversible structure of IrCoOx during the OER and the suppression of over‐oxidation of Co and Ir, giving rise to high stability. Density functional theory calculations reveal that the local geometric ligand engineering optimizes the binding of oxygenated species to the active sites, resulting in strongly enhanced catalytic activity. [ABSTRACT FROM AUTHOR]

In this study, two new Schiff base ligands, (E)-ethyl 2-(2-hydroxybenzylideneamino)-5,5,7,7-tetramethyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate (L1) and (E)-ethyl 2-(2-hydroxy-3-methoxybenzylideneamino)-5,5,7,7-tetramethyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate (L2), and their corresponding RuII complexes, [L1Ru(p-cymene)]Cl·2.5H2O (1) and [L2RuCl(p-cymene)]1.5H2O (2), were synthesized. The structures of Schiff bases and their RuII‐p‐cymene complexes were elucidated using microanalysis, magnetic susceptibility, molar conductivity, 1H-NMR, 13C-NMR, FT-IR, UV–Vis, LC–MS, and thermogravimetric analysis techniques. Octahedral structures for the obtained RuII‐p‐cymene complexes were proposed. The catalytic activities of the RuII‐p‐cymene complexes obtained after the characterization processes were investigated by using acetophenone derivatives in the transfer hydrogen reactions. The product conversions obtained as a result of catalytic studies were determined using GC–MS. When 4-bromoacetophenone was used as a substrate in the transfer hydrogen reactions, catalysts 1 and 2 showed good catalytic activity of 93% and 96%. [ABSTRACT FROM AUTHOR]

Oxygen reduction and evolution reactions (ORR/OER) have attracted tremendous attention as the means to provide sustainable energy solutions. Bifunctionality for ORR and OER is extremely crucial and relevant for regenerative fuel cell technology. Both reactions use precious metal-based electrocatalysts that are limited and expensive making a strong case to develop low-cost, active and stable electrocatalysts. We propose tailoring of Cobalt Porphyrin (Co–Pr) framework by introducing meso phenyl substituents in the Pr ligand and further substitution of phenyl group by ortho/para-anilino groups (CoTPP, CoTPP-o-NMe 3 , CoTPP-p-NMe 3) to design an efficient and selective bifunctional catalyst. Electrocatalysis by CoTPP-o-NMe 3 (ηORR/ηOER = 0.45/0.28 V) outperforms Ir/Ru and Pt based benchmark catalysts. Energy profile, scaling relationship, electrode potential, energy descriptor and FMO analysis performed in the DFT framework rationalize its excellent catalytic activity and selectivity for 4e− reduction of O 2 to H 2 O which is vital for hydrogen production and fuel cell applications. • Tailoring meso positions of Co-Pr to enhance its catalytic activity for ORR/OER. • CoTPP-o-NMe 3 , the best bifunctional catalyst with ηORR/ηOER of 0.45/0.28 eV. • Outperforms the benchmark Pt and Ir/Ru catalysts for ORR/OER. • Efficient even in presence of electrode potential. • Promotes 4e- selective reduction of O 2 to H 2 O. [Display omitted] [ABSTRACT FROM AUTHOR]

Molecular hydrogen (H 2) is one of the future energy carriers when replacing fossil sources. Enzymatic systems serve as an inspiration for the design of novel hydrogen evolving catalysts. Though several heterobimetallic Ru systems are known as catalysts for the hydrogen evolution reaction (HER), homogeneous mononuclear Ru systems have not been explored much. Here, a new mononuclear Ru(II) complex [ cis -RuCl 2 (PPh 3) 2 (κ 2- TL)] (TL = 2-thiophenyl benzimidazole) possessing distorted octahedral geometry, has been synthesised and characterized as an efficient catalyst for acid-assisted hydrogen evolution by using various spectroscopic techniques as well as quantum chemical calculations. When trifluoroacetic acid is used as the proton source, the complex shows remarkable catalytic activity towards H 2 production. Based on the DFT calculations, an EECC mechanism could be proposed for HER, consistent with the assignment of the observed redox transitions. • Interdisciplinary research on energy and environmental catalysis is required to develop renewable sources of energy. • Hydrogen has emerged as an alternative energy carrier due to its carbon-free burning. • Enzymatic systems serve as an inspiration for the design of novel hydrogen evolving catalysts. • Very few bio-inspired homogeneous mononuclear Ru mimics have been explored as HER electrocatalysts. • The reported work reveals design principles for future HER catalysts that can operate at ambient conditions. [ABSTRACT FROM AUTHOR]

On-site hydrogen production from the oxidative decomposition of NH 3 with a catalyst is highly required in the countryside where external heat is hardly supplied. In this study, Ru-based zeolite catalysts were prepared by impregnation and subsequent washing using RuCl 3 ·3H 2 O and HY zeolite or H-MOR zeolite for the oxidative decomposition of NH 3. The H-MOR-supported Ru catalyst could not be self-heated by feeding 80% NH 3 /20% O 2 to the catalyst bed at room temperature. By contrast, the HY-supported Ru catalyst underwent self-heating to approximately 773 K upon feeding the reactants owing to the heat released by NH 3 adsorption and oxidation, leading to excellent performance for the oxidative decomposition of NH 3 during five cycles of start-up tests. Characterization results indicated that the Cl-free Ru/HY catalyst exhibited self-heating due to the presence of small well-dispersed Ru metal particles and a large amount of surface acidic sites. [Display omitted] • HY or H-MOR zeolite was selected as a support for Ru-based zeolite catalysts. • Cl-free Ru/HY catalyst underwent self-heating to approximately 773 K upon feeding 80%NH 3 /20%O 2. • Cl species presented on the catalyst was needed for self-heating of Ru/H-MOR catalyst bed. • Cl-free Ru/HY catalyst exhibited stable catalytic activity during five start-up cycles. • This attributes to the presence of small well-dispersed Ru particles and a large amount of acid sites. [ABSTRACT FROM AUTHOR]

Reducible WO3 powder with a mean diameter of 100 nm is used as support to stabilize ruthenium(0) nanoparticles. Ruthenium(0) nanoparticles are obtained by NaBH4 reduction of ruthenium(III) precursor on the surface of WO3 support at room temperature. Ruthenium(0) nanoparticles are uniformly dispersed on the surface of tungsten(VI) oxide. The obtained Ru0/WO3 nanoparticles are found to be active catalysts in hydrolytic dehydrogenation of ammonia borane. The turnover frequency (TOF) values of the Ru0/WO3 nanocatalysts with the metal loading of 1.0%, 2.0%, and 3.0% wt. Ru are 122, 106, and 83 min-1, respectively, in releasing hydrogen gas from the hydrolysis of ammonia borane at 25.0 °C. As the Ru0/WO3 (1.0% wt. Ru) nanocatalyst with an average particle size of 2.6 nm provides the highest activity among them, it is extensively investigated. Although the Ru0/WO3 (1.0% wt. Ru) nanocatalyst is not magnetically separable, it has extremely high reusability in the hydrolysis reaction as it preserves 100% of initial catalytic activity even after the 5th run of hydrolysis. The high activity and reusability of Ru0/WO3 (1.0% wt. Ru) nanocatalyst are attributed to the favorable metal-support interaction between the ruthenium(0) nanoparticles and the reducible tungsten(VI) oxide. The high catalytic activity and high stability of Ru0/WO3 nanoparticles increase the catalytic efficiency of precious ruthenium in hydrolytic dehydrogenation of ammonia borane. [ABSTRACT FROM AUTHOR]

• Ce-doped TiO 2 supported RuO 2 catalyst with a low Ru loading was developed for the Deacon reaction. • The resultant catalyst exhibited an excellent catalytic activity even under oxygen-lean condition. • Elucidation on the effects of the doped Ce in the catalytic oxidation of HCl. Reducing the cost of RuO 2 /TiO 2 catalysts is still one of the urgent challenges in catalytic HCl oxidation. In the present work, a Ce-doped TiO 2 supported RuO 2 catalyst with a low Ru loading was developed, showing a high activity in the catalytic oxidation of HCl to Cl 2. The results on some extensive characterizations of both Ce-doped TiO 2 carriers and their supported RuO 2 catalysts show that the doping of Ce into TiO 2 can effectively change the lattice parameters of TiO 2 to improve the dispersion of the active RuO 2 species on the carrier, which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions. This work provides some scientific basis and technical support for chlorine recycling. Ce-doped TiO 2 supported RuO 2 catalyst with a low Ru loading was developed for the catalytic oxidation of HCl to Cl 2 , exhibiting an excellent catalytic activity and a good stability. [Display omitted] [ABSTRACT FROM AUTHOR]

The possibility of using ruthenium in the composition of palladium–rhodium catalysts used to neutralize the exhaust gases of vehicles with gasoline engines was investigated. The thermolysis of a supported precursor in oxidizing and reducing atmospheres led to the formation of samples with different initial catalytic activity. The stability of trimetallic systems was compared under conditions of prompt thermal aging with that of reference samples of similar chemical composition but obtained by mechanical mixing of monometallic catalysts. The results obtained allowed us to conclude that the alloy nanoparticles were more stable, and the thermolysis of the precursor in a reducing atmosphere contributed to a higher initial activity of the catalyst in the oxidation of CO. According to the X-ray photoelectron spectroscopy data, the high thermal stability of trimetallic catalysts was due to a constant ratio between metals on the support surface in the course of the catalytic reaction. [ABSTRACT FROM AUTHOR]

Transition‐metal‐catalyzed acceptorless dehydrogenative coupling (ADC) has emerged as a sustainable synthetic strategy for the construction of N‐heteroaromatics. Herein, a series of water‐soluble amidato Ru catalysts were designed, synthesized, and utilized in the selective synthesis of 2‐substituted benzimidazoles from the aromatic diamines and primary alcohols, as well as 2‐substituted quinolines from the substituted 2‐aminobenzyl alcohols and acetophenones via the ADC strategy in water. Catalyst 1 d bearing a strong electron‐donating hydroxyl group on the ligand exhibited the best catalytic activity. The catalytic system demonstrated remarkable efficiency and versatility, allowing for the application of over 40 substrates in two ADC reactions with good to high yields. Based on control experiments and density functional theory (DFT) calculations, a plausible mechanism was proposed, highlighting the significant role of functionalized amidato Ru complexes in catalyzing alcohol dehydrogenation via an outer‐sphere pathway. [ABSTRACT FROM AUTHOR]

The development of a bifunctional ruthenium-based electrocatalyst that can efficiently and economically drive both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) remains challenging because ruthenium species can undergo severe agglomeration during preparation which can significantly reduce the catalytic activity. Constructing supported metal catalysts can not only improve the stability of Ru but also improve the catalytic performance by adjusting the electronic structure, which is an effective way to solve the current challenges. In this paper, Ru-loaded MoO2/MoO3 heterostructures (Ru–MoOx) with oxygen vacancies were successfully synthesized by controlling the annealing temperature. This special structure can effectively tune the electronic structure, enhance the electrical conductivity and increase the active sites, thus improving the catalytic activity of the catalyst. Performance studies have shown that Ru–MoOx exhibits excellent HER and OER performance in alkaline media. And it is not surprising that the overall water decomposition performance of Ru–MoOx is also excellent, requiring only a cell voltage of 1.54 V to reach 10 mA cm−2. [ABSTRACT FROM AUTHOR]