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Herein we demonstrate an effective and facile end‐capping technique for ring‐opening metathesis polymerization (ROMP) using readily available allyl compounds as a new type of terminating agents. This new type of end‐capping reactions, which are based on the base‐promoted decomposition of ruthenocyclobutane intermediates, introduce diene moiety onto the chain end of ROMP polymers while simultaneously deactivating the ruthenium complex. These termination reactions are highly efficient, typically completing within 1 minute at 0 °C with >95 % end‐capping fidelity. [ABSTRACT FROM AUTHOR]

Due to its abundant resources and advantages in transportation and storage, methane fueled solid oxide fuel cells (SOFCs) are highly needed. In this work, an exceptional internal reforming catalyst comprising in-situ exsolved NiRu bimetallic nanoparticles and oxygen-deficient layered double perovskite LaBaMn 1.6 Ni 0.3 Ru 0.1 O 5+δ (r-LBMNR) was prepared. Compared to the cell with LaBaMn 1.6 Ni 0.4 O 5+δ (r-LBMN) catalyst, the cell with a Ru-doping r-LBMNR catalyst layer, exhibits superior peak power output of 336 mW cm−2 and better durability with a less decay rate of 0.014% per hour in CH 4 fuel. The enhanced electrochemical performance can be attributed to the high oxygen ion and electron conductivities of the catalyst and the coupling of Ni and Ru sites with the oxygen-deficient r-LBMNR matrix This coupling activates CH 4 and H 2 O, promotes the oxidation of C atoms in CH 4 molecules, and enables reversible hydrogen spillover, ultimately leading to the production syngas of CO(g) and H 2 (g). [Display omitted] • Trace Ru-doping facilitating the exsolution of nanoparticles. • LaBaMn 1.6 Ni 0.3 Ru 0.1 O 5+δ was modified with abundant O v and exsolved NiRu alloy. • Cell can operate stably over 220 h with a degradation rate of 0.014% h−1. [ABSTRACT FROM AUTHOR]

The immobilization of Hoveyda–Grubbs form of metathesis catalyst (Z.C.) exhibited simple non-covalent interactions with the mesoporous SBA-15. It was discovered that the Z.C. catalyst worked well to speed up the citronellene ring closing metathesis reaction. Using cyclohexane as a solvent, the citronellene ring closing metathesis reaction was performed at various temperatures. A very low (almost negligible) catalyst leaching was observed. A high turnover number (TON) was obtained by using a very small amount of catalyst. The activation energy was calculated in the case of ring closing metathesis reaction of citronellene at different temperatures. By using the high concentration of citronellene, a high TON was obtained (4674), which indicates that active catalytic centers were not demolished by a large concentration of citronellene molecule. Turnover number (264) was produced when the Ru/substrate molar ratio 1:300 used in the reaction. [ABSTRACT FROM AUTHOR]

The direct diastereo‐ and enantioselective Ru(II)‐ catalyzed cyclopropanation reaction of alkenes with ((2‐diazo‐1,1‐difluoroethyl)sulfinyl)benzene was described. The desired enantioenriched PhSO2CF2‐cyclopropanes were obtained in high yields with high diastereo‐ and enantioselectivities in the presence of a chiral ruthenium complex Ru(II)‐Pheox (17–94% yields, >20:1 d.r. and 83:17–98:2 e.r.). The robustness of the approach was showcased and This methodology gave access to chiral 1,2‐trans difluoro‐methylcyclopropanes. [ABSTRACT FROM AUTHOR]

The efficient transformation of chemicals and electricity via electrocatalytic hydrogen evolution reaction (HER) plays a pivotal role in green hydrogen production. Both in academia and industry, the pursuit of designing and fabricating catalysts for HER that are not only efficient and robust but also environmentally friendly is of significant interest. In this work, a ruthenium catalyst doped with nickel was synthesized using a procedure-minimal and solvent-free method facilitated by microwave-assisted pyrolysis. The incorporation of alloying and optimized electronic structures has resulted in Ru-based nanocrystals that change the HER mechanism and enable enhanced activity. The optimal RuNi/C catalyst demonstrates an overpotential of only 15 mV at a current density of 10 mA cm−2, with a Tafel slope of 24 mV dec−1, surpassing the performance of the state-of-the-art Pt/C catalyst. Remarkably, the prepared catalyst exhibits admirable corrosion resistance, making it a highly promising candidate for green hydrogen production through seawater splitting. A ruthenium catalyst doped with nickel is synthesized through a solvent-free microwave treatment, and exhibits a Pt-surpassed activity towards HER. [Display omitted] • A ruthenium catalyst doped with nickel is synthesized via a green method. • The HER mechanism on ruthenium is transferred by the doped nickel. • The optimized catalyst shows a platinum-surpassed activity for HER. • Superior corrosion resistance and durability is achieved for seawater splitting. [ABSTRACT FROM AUTHOR]

In this study, we investigated the mechanism of the inactivated hexene hydrogenation reaction catalyzed by a ruthenium (II) complex containing "N‐heterocyclic carbene" (NHC) ligands, specifically SIMes and CBA, using DFT calculations. Our focus was on RuH(OSO2CF3)(CO)(SIMes)(CBA), which exhibits excellent catalytic behavior. We tested the B3LYP‐D3, cam‐B3LYP, and TPSSh functionals. The hydrogenation reaction is initiated by the release of SIMes rather than CBA due to the lower associated dissociation energy. Our findings indicate a reaction mechanism consisting of two consecutive steps, each involving one hydrogen atom migration. The first step, considered as the kinetically limiting transition state, exhibits a Gibbs free activation barrier of 12.9 kcal mol−1. This step involves two asynchronous processes. The first one describes the migration of the ruthenium hydride to the internal carbon of the olefine function, transitioning from π to σ coordination mode, which promotes the formation of a bond between ruthenium and the terminal olefinic carbon. The second process involves the oxidation of ruthenium from Ru(II) to Ru(IV). This oxidation is crucial as it enables the decomposition of the H2 molecule into two hydrogen atoms bonded to the ruthenium atom. The geometrical structures of the Hidden Reaction Intermediate Ru(II) complex and the quasi‐transition state of the second process have been determined by means of the RIRC technique. The second step entails the migration of one of the newly formed hydrides of the Ru(IV) complex to the terminal olefinic carbon, resulting in the release of hexane with a weak activation Gibbs free energy of.8 kcal mol−1. Lastly, we explored the use of dichloromethane as a solvent, considering the PCM model. The presence of the solvent significantly decreases the energy dissociation of SIMes from 17.9 to 9.0 kcal mol−1, providing notable benefits. [ABSTRACT FROM AUTHOR]

The performance of a set of bimetallic Ru-Co catalysts dispersed on the TiO2 anatase phase, synthesized by the co-deposition–precipitation with urea method, was tested in the CO2 production by the entire oxidation of C3H8. The presence of properly dispersed ruthenium nanoparticles on a Co/TiO2-anatase support was notably favorable for enhancing the C3H8 activity/selectivity. Likewise, an increase in the combined acidity (Brönsted and Lewis) was also observed, and the interaction between Ru0-CoOx species stabilized on TiO2 prompted the C3H8 oxidation at low temperature. The performance of bimetallic Ru-Co/TiO2 catalysts was enhanced by increasing Ru0 species and loading, showing more efficient C3H8 oxidation by the combination of Ru0-CoOx, as revealed by DRIFTS, XPS, H2-TPR, and HAADF-STEM characterization outcomes. The higher acidity of the catalysts containing Ru (1.5 wt%) and Co (3 wt%) as well as the reducibility enhancement of the Ru and Co species led to the best capacity of these catalysts for C3H8 oxidation to CO2 under the experimental conditions employed in this study. [ABSTRACT FROM AUTHOR]

Diarylacetylenes ArC≡CAr featuring condensed aromatic hydrocarbon fragments (Ar) such as naphthalene, anthracene, phenanthrene and pyrene were converted into vinylidene ligands by 1,2‐migration reactions within the coordination sphere of half‐sandwich complexes [MII(dppe)Cp]+ (MII = RuII, FeII). Comparison of the extent of conversion of the alkyne substrates to the vinylidene complexes [Ru{=C=CAr2}(dppe)Cp]+ with those obtained from acetylenes functionalized by smaller groups (H, CH3, Ph) show that the molecular volume (VM) of the migrating group and relief of steric congestion plays a role during the rearrangement process. Conversely, the H‐atoms from the larger condensed ring aryl groups that are in close proximity to the migrating sites also have a significant influence on the efficacy and extent of the reaction by restricting access of the alkyne to the metal center, resulting in a less effective migration reaction. This combination of competing steric factors (acceleration due to relief of steric congestion and restricted access of the alkyne moiety to the reaction site) is exemplified by the facile migration of 1‐pyryl entities and the low yields of vinylidene products formed from 1,2‐bis(9‐anthryl)acetylene. [ABSTRACT FROM AUTHOR]

The effectuation of pH‐universal electrocatalysis is highly attractive but still challenging for the hydrogen evolution reaction (HER). It appeals for not only the facilitated electron transport but also the kinetical proton mass transfer. In this study, a via‐hole Ru/MoO2 confined heterostructure is profiled as a metal‐support platform for the electron/mass transfer‐boosted pH‐universal HER studies. It is indicated that the as‐formed Ru─O─Mo bridge can modulate the electronic transport at the interface, and the proton adsorption and transfer are kinetically derived by the intensified metallic Ru─Ru bond. Resultantly, the Ru/MoO2 heterostructure stably attains the Pt‐beyond HER activity with an ultralow overpotential of 9.2 mV at 10 mA cm−2 in 1 m KOH, and also achieves the competitive HER activity and stability in the acidic/neutral electrolytes. Both the experimental and computational results reveal the accelerated HER kinetics is attributable to the intensive mass transfer through the interfacial Ru→MoO2 hydrogen spillover effect. This work opens up the opportunities to rationalize the advanced metal‐support HER electrocatalysts through the interfacial hydrogen spillover effect and metallic bond engineering. [ABSTRACT FROM AUTHOR]

The catalytic efficacy of ruthenium (Ru)-exchanged montmorillonite, a well-established heterogeneous catalyst, was systematically explored to synthesize diverse bis(indolyl)methanes. The developed methodology consistently yielded the desired products with satisfactory to excellent yields, while notable advantages of the proposed approach encompassed minimal reaction times and solvent-free conditions. Furthermore, the method was characterized by its procedural simplicity, facile catalyst synthesis, ready accessibility of the starting materials from commercial sources, and the potential for catalyst recyclability. [ABSTRACT FROM AUTHOR]

[Display omitted] Catalysts composed of nanocluster and single-atom (SA) were extensively used to enhance electrocatalytic water splitting performance, whereas study of their photocatalytic hydrogen (H 2) evolution activity was limited. Herein, carbon nitride (CN) decorated by ruthenium (Ru) cocatalysts existed as SA + cluster, cluster + nanoparticles (NPs), and NPs were prepared by impregnation and calcination processes. The correlation between existential form, content of Ru cocatalyst and H 2 evolution rate were carefully discussed. It was found that Ru NPs were favor for water molecule adsorption, whereas Ru SAs and clusters facilitated H 2 desorption. Theoretical calculations revealed that Ru clusters + NPs cocatalyst were beneficial for H* intermediate formation. Water splitting tests found that 1.07 wt% Ru NPs + cluster modified CN showed the highest H 2 evolution rate of 13.64 mmol h−1 g−1, which was 266.4 and 1.5 times higher than those of CN and Ru NPs (2.33 wt%) decorated CN, respectively. This work deeply reveals the influences of existential form of Ru cocatalysts on photocatalytic water splitting of CN, and provides thought in designing new cocatalysts to largely enhance H 2 evolution. [ABSTRACT FROM AUTHOR]

The ruthenium (Ru)-based functional structure has been well understood in catalytic performance due to its special particularity in structural fabrication. In this work, the controllable synthesis of core–shell Ru nanomaterials is first reported, which were not only realized via ice bath conditions with amorphous characterization but also showed a flexible design in the controllable synthesis of crystalline Ru after high intensity focused ultrasound (HIFU) treatment. The achieved amorphous Ru particles (∼115 ± 3 nm) and crystalline Ru (∼5 ± 0.5 nm) exhibit hydrogen peroxide catalytic performance and can be considered as an electrochemical sensing platform. The Km value of core–shell Ru for 3,3′,5,5′-tetramethylbenzidine (TMB) was 0.221 mM, which exhibits higher affinity for TMB and prominent catalytic performance than horseradish peroxidase (HRP). For selectivity and sensitivity towards the detection of H2O2 molecules, it expressed a wide linear range from 0.5 to 100 mM with an H2O2 detection limit of 1.45 μM (S/N = 3) and a sensitivity of 2.07 μA μM−1. After HIFU treatment, the diameter of the achieved crystalline Ru was about one-twentieth that of the core–shell Ru structure. An enhancement in catalytic performance was observed as a sensor platform for detecting H2O2, its detection range was wider, from 0.5 to 110 mM, its limit of detection was 0.007 μM (S/N = 3), and it exhibited a higher sensitivity of 443 μA μM−1. Hence, this flexible design in the synthesis of Ru NMs (amorphous and crystalline in status) could provide a novel synthetic strategy and make achievements in catalytic performance. [ABSTRACT FROM AUTHOR]

A novel phosphine‐free ruthenium pincer complex based on an NNN pincer ligand has been prepared and fully characterized. The complex was subsequently employed as an efficient catalyst for the N‐methylation of amines and the direct N‐methylation of nitroarenes using methanol as a C1 source under mild reaction conditions following the borrowing‐hydrogen approach. Both of the catalytic transformations were performed with only catalytic amounts of base under closed air conditions without using any other additives. [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 is discussed. Through these discussions, a comprehensive understanding of Ru‐based heterostructure catalysts and inspire future research directions is aim to provided. [ABSTRACT FROM AUTHOR]

The late‐stage functionalization of active pharmaceutical ingredients is a key challenge in medicinal chemistry. Furthermore, N‐aryl triazoles and tetrazoles are important structural motifs with the potential to boost the activity of diverse drug molecules. Using easily accessible dibenzothiophenium salts for the ruthenium‐catalyzed C−H arylation, these scaffolds were introduced into a variety of bioactive compounds. Our methodology uses cost‐efficient ruthenium, KOAc as a mild base and gives access to a plethora of highly decorated triazole and tetrazole containing drug derivatives. [ABSTRACT FROM AUTHOR]

Ruthenium (Ru) is a promising electrocatalyst for the hydrogen evolution reaction (HER), despite suffering from low activity in non‐acidic conditions due to the high kinetic energy barrier of H2O dissociation. Herein, the synthesis of carbon nanosheet‐supported RuP/Ru heterostructures (RuP/Ru@CNS) from a natural polysaccharide is reported and demonstrates its behavior as an effective HER electrocatalyst in non‐acidic conditions. The RuP/Ru@CNS exhibits low overpotential (106 mV at 200 mA·cm−2) in alkaline electrolyte, exceeding most reported Ru‐based electrocatalysts. The electron shuttling between Ru atoms at the RuP/Ru interface results in a lowered energy barrier for H2O dissociation by electron‐deficient Ru atoms in the pure Ru phase, as well as optimized H* adsorption of electron‐gaining Ru atoms in the neighboring RuP. A low H* spillover energy barrier between Ru atoms at the RuP/Ru interface further boosts HER kinetics. This study demonstrates a sustainable method for the fabrication of efficient Ru‐based electrocatalysts and provides a more detailed understanding of interface effects in HER catalysis. [ABSTRACT FROM AUTHOR]

This study prepared a series of cerium oxide-based catalysts with different metal ruthenium loadings using an initial wet impregnation method. The results demonstrate that the prepared 1.4Ru/CeO 2 catalyst exhibits outstanding catalytic performance and activity stability. Under the condition where the Ru loading is only 1.4 wt%, the catalyst achieves almost complete NH 3 conversion at 500 °C, with a hydrogen production rate of 16.59 mmol gcat−1 min−1. Furthermore, after a 48-h long-term test, the activity remains stable. Characterization tests show that the metal ruthenium is uniformly distributed on the surface of cerium dioxide, with particle sizes ranging from 3 to 6 nm. Notably, a structure characterized by lattice stripes overlapping between the metal and support is observed. Increasing the Ru loading can enhance the surface acidity sites of the catalyst and the interaction between the metal and the support, which plays a crucial role in the long-term stability of the catalyst. Additionally, the abundant oxygen vacancies in cerium dioxide and its low cerium oxidation-reduction potential facilitate electron transfer to ruthenium, enhancing the adsorption of NH 3 and accelerating the desorption of N 2. [Display omitted] • The catalytic performance is related to the dispersion of the metal and the oxygen vacancies on the surface of the support. [ABSTRACT FROM AUTHOR]

Isomerization Metathesis (ISOMET) reaction is an emerging tool for "open loop" chemical recycling of polyethylene to propylene. Novel, latent N‐Alkyl substituted Cyclic(Alkyl)(Amino)Carbene (CAAC)–ruthenium catalysts (5a‐Ru, 3b‐Ru – 6c‐Ru) are developed rendering "inverted" chemical structure while showing enhanced ISOMET activity in combination with (RuHCl)(CO)(PPh3)3 (RuH) double bond isomerization co‐catalyst. Systematic investigations reveal that the steric hindrance of the substituents on nitrogen and carbon atom adjacent to carbene moiety in the CAAC ligand have significantly improved the catalytic activity and robustness. In contrast to the NHC‐Ru and CAAC‐Ru catalyst systems known so far, these systems show higher isomerization metathesis (ISOMET) activity (TON: 7400) on the model compound 1‐octadecene at as low as 3.0 bar optimized pressure, using technical grade (3.0) ethylene. The propylene content formed in the gas phase can reach up to 20% by volume. [ABSTRACT FROM AUTHOR]

The porous architectures of oxygen cathodes are highly desired for high-capacity lithium–oxygen batteries (LOBs) to support cathodic catalysts and provide accommodation for discharge products. However, controllable porosity is still a challenge for laminated cathodes with cathode materials and binders, since polymer binders usually shield the active sites of catalysts and block the pores of cathodes. In addition, polymer binders such as poly(vinylidene fluoride) (PVDF) are not stable under the nucleophilic attack of intermediate product superoxide radicals in the oxygen electrochemical environment. The parasitic reactions and blocking effect of binders deteriorate and then quickly shut down the operation of LOBs. Herein, the present work proposes a binder-free three-dimensional (3D) porous graphene (PG) cathode for LOBs, which is prepared by the self-assembly and the chemical reduction of GO with triblock copolymer soft templates (Pluronic F127). The interconnected mesoporous architecture of resultant 3D PG cathodes achieved an ultrahigh capacity of 10,300 mAh g−1 for LOBs. Further, the cathodic catalysts ruthenium (Ru) and manganese dioxide (MnO2) were, respectively, loaded onto the inner surface of PG cathodes to lower the polarization and enhance the cycling performance of LOBs. This work provides an effective way to fabricate free-standing 3D porous oxygen cathodes for high-performance LOBs. [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]

Robert H Grubbs (1942–2021), Nobel laureate and former professor of Caltech, USA, is celebrated for his path breaking discovery of a series of ruthenium carbene based organometallic catalysts, well known as Grubbs catalysts. These catalysts are widely used by chemists across the world for carrying out a variety of olefin metathesis reactions under mild and ambient conditions. The article describes the synthesis and development of Grubbs ruthenium carbene catalysts and their closely related analogues. Their differences in structure, reactions and properties, their advantages and disadvantages when applied as catalysts in olefin metathesis reactions are briefly highlighted. [ABSTRACT FROM AUTHOR]

This article presents a study on the synthesis of pyrido[1,2-a:4,3-b']diindoles through a ruthenium-catalyzed coupling/cyclization reaction. The researchers investigated the reaction conditions and found that electron-donating groups and certain substitutions on the indole ring were well tolerated, resulting in good yields of the desired products. The proposed reaction pathway involves the formation of a ruthenacycle intermediate, followed by the insertion of a sulfur ylide and subsequent cyclization. The authors suggest that these pyrido[1,2-a:4,3-b']diindole derivatives may have potential pharmaceutical applications. [Extracted from the article]

The paper describes an investigation into hydrogenation of furfural over ruthenium catalysts supported on porous aromatic frameworks. The supports were designated as PAF-30-SO3H, PAF-30-NH2, and PAF-30. The synthesized catalysts were tested in furfural hydrogenation carried out in water and in tetrahydrofuran (with a concentration of 10 wt %) at 90–250°C and a hydrogen pressure of 3 MPa. Although the highest furfural conversion (96%) was achieved in the case of its hydrogenation in water at 250°C over Ru-PAF-30, these conditions did not favor product selectivity. The reaction products mainly consisted of furfuryl alcohol, tetrahydrofurfuryl alcohol, and cyclopentanone. The highest yield of cyclopentanone, 71% (with 80% conversion and 89% selectivity) was observed in furfural hydrogenation over Ru-PAF-30 at 200°C, whereas the conditions optimal for selective hydrogenation of furfural into furfuryl alcohol were found to include either tetrahydrofuran as a solvent or water as a solvent and low temperatures (90–150°C). [ABSTRACT FROM AUTHOR]

Nanostructured ionic compounds have driven major technological advancements in displays, photovoltaics, and catalysis. Current research focuses on refining the chemical composition of such compounds. In this study, a strategy for creating stoichiometrically well‐defined nanoscale multiple‐cation systems, where the atomically precise structure maximizes the synergistic cooperation between cations at the atomic scale is reported. The unprecedented construction of Heusler‐type PtRuP2 double‐walled nanotubes through sequential anion/cation exchange reactions is demonstrated. The PtRuP2 catalyst exhibits record‐high catalytic performance and durability for the hydrogen evolution reaction (HER) in alkaline electrolytes and anion‐exchange membrane water electrolyzers. The investigations highlight the crucial role of Pt/Ru dual centers, providing multiple active sites that accelerate the HER kinetics within a single phosphide material, in the sequential operation of H2O activation/dissociation at Ru and H2 production at adjacent Pt sites. These findings open new avenues for optimizing ionic compound‐based HER electrocatalysts, offering platinum‐metal alternatives in acidic and alkaline media. [ABSTRACT FROM AUTHOR]

Colloidal Ru nanoparticles (NP) display interesting catalytic properties for the hydrogenation of (hetero)arenes as they proceed efficiently in mild reaction conditions. In this work, a series of Ru based materials was used in order to selectively hydrogenate quinaldine and assess the impact of the stabilizing agent on their catalytic performances. Ru nanoparticles stabilized with polyvinylpyrrolidone (PVP) and 1‐adamantanecarboxylic acid (AdCOOH) allowed to obtain 5,6,7,8‐tetrahydroquinaldine with a remarkable selectivity in mild reaction conditions by choosing the suitable solvent. The presence of a carboxylate ligand on the surface of the Ru NP led to an increase in the activity when compared to Ru/PVP catalyst. The stabilizing agent had also an impact on the selectivity, as carboxylate ligand modified catalysts promoted the selectivity towards 1,2,3,4‐tetrahydroquinaldine, with bulky carboxylate displaying the highest ones. [ABSTRACT FROM AUTHOR]

With the large consumption of fossil energy, people began spend attention and energy to find and unearth renewable energy, and electrolytic water hydrogen evolution is an ideal scheme. The key to hydrogen production from electrolytic water is to find an appropriate catalyst. Here, we have developed an efficient and durable catalyst by introducing Ruthenium into porous graphene oxide (Ru@PGO), When the current density is 10 mA cm−2, the the corresponding overpotential and Tafel slope are 40.2 mV and 89.68 mV dec−1 respectively, and its stability is very excellent. Through theoretical calculation, it is found that ΔGH* is low, and reveals the effect of pore structure and oxygen introduction on the catalyst. It provides a feasible scheme for the preparation of new catalyst for hydrogen evolution reaction (HER). [ABSTRACT FROM AUTHOR]

Anions of carboxylic acids are widely used as the promoters of ruthenium-catalyzed reactions of C—H activation of substrates containing an N-donar directing group. The promoting effect of structure of anions of aliphatic and (hetero)aromatic carboxylic acids on the C—H arylation of benzene, furan, and thiophene rings in benzo[d]imidazol-2-yl-(hetero)arenes, wherein the benzimidazole moiety played the role of N-donor directing group, was evaluated. It was found that the structural effect of carboxylate anion on the efficiency of promotion of the catalytic system can significantly vary upon the arylation of different substrates. Adamantane-1-carboxylic acid was proposed as the most effective and universal promoter, based on which a new efficient catalytic system was developed for the selective arylation of benzo[d]imidazol-2-yl-(hetero)arenes. [ABSTRACT FROM AUTHOR]

A ruthenium‐catalyzed C(sp2)−H acyloxylation of 2‐aroyl pyridine derivatives with simple sodium carboxylate utilizing transformable directing groups is described. This protocol features broad functional group tolerance and chemo‐ and regio‐selectivity, providing the acyloxylation products in 45%‐84%yield. Furthermore, the synthetic utility of this protocol was demonstrated by the late‐stage functionalization of pharmaceutical compounds. Notably, the acyloxylation products could be further transformed into a variety of useful heterocycles under mild conditions. [ABSTRACT FROM AUTHOR]

An atom‐ and step‐economical and redox‐neutral cascade reaction enabled by asymmetric bimetallic relay catalysis by merging a ruthenium‐catalyzed asymmetric borrowing‐hydrogen reaction with copper‐catalyzed asymmetric Michael addition has been realized. A variety of highly functionalized 2‐amino‐5‐hydroxyvaleric acid esters or peptides bearing 1,4‐non‐adjacent stereogenic centers have been prepared in high yields with excellent enantio‐ and diastereoselectivity. Judicious selection and rational modification of the Ru catalysts with careful tuning of the reaction conditions played a pivotal role in stereoselectivity control as well as attenuating undesired α‐epimerization, thus enabling a full complement of all four stereoisomers that were otherwise inaccessible in previous work. Concise asymmetric stereodivergent synthesis of the key intermediates for biologically important chiral molecules further showcases the synthetic utility of this methodology. [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]

Two rigid β-elimination immune PCcarbeneP pincer ligands, differing in their electron donor properties by variation of the substitution pattern on the aromatic linker arms, were complexed to ruthenium to form the dichlorides LRRuCl2 (R = H or NMe2). These compounds were converted to hydrido chlorides by treatment with dihydrogen (H2) and a base. By converting to tert-butoxide derivatives in situ under an atmosphere of H2, the poly hydride PCalkylP complexes LHRRu(H)3 compounds were generated. In these complexes, H2 has added across the Ru＝C bond in the PCcarbeneP starting materials. The polyhydrides are dynamic in solution and extensive NMR studies helped to elucidate the speciation and fluxional processes operative in this dynamic system. The polyhydride complexes react rapidly with CO2 to give the PCcarbeneP formato hydride complexes LRRu(H)-κ2-O2CH. For R = H, the 1,2-hydride shift from the anchoring alkyl of the PCalkylP carbon to the metal is reversible, but for R = NMe2 it is irreversible. The CO2 incorporated into the formato ligand of these compounds exchanges with free CO2via a bimolecular mechanism that is more rapid for R = NMe2 than for R = H; plausible explanations for this observation are proffered. Experiments designed to evaluate the efficacy of the R = NMe2 formato hydride complex as a catalyst precursor for CO2 hydrogenation to formate salts reveal poor performance in comparison to state-of-the-art ruthenium-based catalysts. This is due primarily to the precipitation of a dimeric μ-κ2-κ1-CO3 carbonate complex that is not an active catalyst for the reaction. [ABSTRACT FROM AUTHOR]

Two rigid β-elimination immune PCcarbeneP pincer ligands, differing in their electron donor properties by variation of the substitution pattern on the aromatic linker arms, were complexed to ruthenium to form the dichlorides LRRuCl2 (R = H or NMe2). These compounds were converted to hydrido chlorides by treatment with dihydrogen (H2) and a base. By converting to tert-butoxide derivatives in situ under an atmosphere of H2, the poly hydride PCalkylP complexes LHRRu(H)3 compounds were generated. In these complexes, H2 has added across the Ru＝C bond in the PCcarbeneP starting materials. The polyhydrides are dynamic in solution and extensive NMR studies helped to elucidate the speciation and fluxional processes operative in this dynamic system. The polyhydride complexes react rapidly with CO2 to give the PCcarbeneP formato hydride complexes LRRu(H)-κ2-O2CH. For R = H, the 1,2-hydride shift from the anchoring alkyl of the PCalkylP carbon to the metal is reversible, but for R = NMe2 it is irreversible. The CO2 incorporated into the formato ligand of these compounds exchanges with free CO2via a bimolecular mechanism that is more rapid for R = NMe2 than for R = H; plausible explanations for this observation are proffered. Experiments designed to evaluate the efficacy of the R = NMe2 formato hydride complex as a catalyst precursor for CO2 hydrogenation to formate salts reveal poor performance in comparison to state-of-the-art ruthenium-based catalysts. This is due primarily to the precipitation of a dimeric μ-κ2-κ1-CO3 carbonate complex that is not an active catalyst for the reaction. [ABSTRACT FROM AUTHOR]

Ligand design is crucial for the design of robust and efficient molecular water oxidation catalysts (WOCs) based on metal complexes. Herein we report the water oxidation studies of a series of Ru WOCs bearing bipyridine dialkoxide ligands with different substituents. Combined with density functional theory (DFT) calculations, the proposed water oxidation mechanism is bimolecular coupling (I2M) of two seven‐coordinate (CN7) Ru=O species. The use of bulky phenyl groups on the planar alkoxide ligand helps to stabilize the high oxidation CN7 intermediates, without loss of ligand flexibility. This strategy may be useful for the design of other active WOCs. [ABSTRACT FROM AUTHOR]

Support effect is an important issue in heterogeneous catalysis, while the explicit role of a catalytic support is often unclear for catalytic reactions. A systematic density functional theory computational study is reported in this paper to elucidate the effect of a model boron nitride (BN) support on the first N-H bond activation step of NH3 on Run (n = 1, 2, 3) metal clusters. Geometry optimizations and energy calculations were carried out using density functional theory (DFT) calculation for intermediates and transition states from the starting materials undergoing the N-H activation process. The primary findings are summarized as follows. The involvement of the model BN support does not significantly alter the equilibrium structure of intermediates and transition states in the most favorable pathway (MFP). Moreover, the involvement of BN support decreases the free energy of activation, ΔG≠, thus improving the reaction rate constant. This improvement is more obvious at high temperatures like 673 K than low temperatures like 298 K. The BN support effect leading to the ΔG≠ decrease is most significant for the single Ru atom case among all three cases studied. Finally, the involvement of the model BN may change the spin transition behavior of the reaction system during the N-H bond activation process. All these findings provide a deeper insight into the support effect on the N-H bond activation of NH3 for the supported Ru catalyst in particular and for supported transition metal catalysts in general. [ABSTRACT FROM AUTHOR]

We reports the ex situ preparation of nanotitania supported ruthenium(0) nanoparticles (NPs) and their catalytic testing in dehydrogenation of dimethylamine borane (DMAB) in toluene solvent. Ru0/TiO 2 NPs are prepared following a 2-step process: Ru3+ ions are first impregnated from the aqueous solution on titania nanopowder and then, reduced by aqueous solution of sodium borohydride. The prepared Ru0/TiO 2 NPs are dried, bottled under inert N 2 gas atmosphere, and used for characterization by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), ICP-OES (inductively coupled plasma optical emission spectroscopy) and XPS (X-ray photoelectron spectroscopy). Ru0/TiO 2 NPs with various Ru loadings are tested as catalysts in hydrogen generation from DMAB and the Ru0/TiO 2 (0.48% wt. Ru) with an average diameter of 6.7 ± 1.3 nm is found to have the highest initial turnover frequency value of 1700 h−1 for the release of 1.0 mol H 2 per mole of DMAB at 60 °C. Results of the recyclability test indicate quite high durability of Ru0/TiO 2 NPs in dehydrogenation of DMAB. [Display omitted] • Ru0/TiO 2 NPs are prepared by impregnation of Ru3+ ions on the surface of titania followed by their reduction. • Ru0/TiO 2 NPs show high catalytic performance in dehydrogenation of dimethylamine borane. • Ru0/TiO 2 (0.48% wt. Ru) provide a record TOF value of 1700 h−1 in this reaction at 60 °C. [ABSTRACT FROM AUTHOR]

Here, carbon quantum dot (CQD) supported Ru nanoparticles from the caffeine in methanol or water by the hydrothermal method were synthesized for the first time to produce hydrogen (H 2) by hydrolysis of ammonia borane(NH 3 BH 3) and their catalytic activities were investigated. The chemical compositions and morphology structures of this caffeine carbon dot-supported Ru catalysts were carefully characterized by UV, PL, TEM, FTIR, and ICP/OES analyses. Well-dispersed Ru nanoclusters with ∼1.81 nm particle size on CQD by the hydrothermal method in methanol medium showed very good catalytic performance. The turnover frequency (TOF) obtained for H 2 production from the catalytic hydrolysis of 5% NH 3 BH 3 with CQD supported Ru catalyst obtained by the hydrothermal method in methanol and water was found to be 361 and 1895 mol H 2 min−1 mol−1, respectively. The activation energies (Ea) for NH 3 BH 3 hydrolysis with the same catalysts were measured as 33.32 and 27.80 kJmol-1, respectively. [Display omitted] • CQD supported Ru nanoparticles in methanol or water by hydrothermal method were synthesized. • CQD supported Ru nanoparticles were used to produce H 2 by hydrolysis of NH 3 BH 3. • Ru@CQD(methanol) nanoclusters with 1.81 nm were prepared by hydrothermal method. • TOF value obtained by Ru@CQD(methanol) was 1895 min−1. • Ea for NH 3 BH 3 hydrolysis by Ru@CQD(methanol) was 27.80 kJmol-1. [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]

The state-of-the-art alkaline hydrogen evolution catalyst of united ruthenium single atoms and small ruthenium nanoparticles has sparked considerable research interest. However, it remains a serious problem that hydrogen evolution primarily proceeds on the less active ruthenium single atoms instead of the more efficient small ruthenium nanoparticles in the catalyst, hence largely falling short of its full activity potential. Here, we report that by combining highly oxophilic cerium single atoms and fully-exposed ruthenium nanoclusters on a nitrogen functionalized carbon support, the alkaline hydrogen evolution centers are facilely reversed to the more active ruthenium nanoclusters driven by the strong oxophilicity of cerium, which significantly improves the hydrogen evolution activity of the catalyst with its mass activity up to −10.1 A mg−1 at −0.05 V. This finding is expected to shed new light on developing more efficient alkaline hydrogen evolution catalyst by rational regulation of the active centers for hydrogen evolution. The Ru single atom-nanocluster alkaline hydrogen evolution catalyst suffers from that hydrogen forms on its less active single atom side. Here, the authors report that oxophilic Ce single atom can reverse the hydrogen formation site to more active Ru nanocluster, enabling enhanced hydrogen evolution capabilities. [ABSTRACT FROM AUTHOR]

The three typical oxygen-containing functional groups on C-dots have been selectively deactivated to elucidate their impact on the co-reactant behavior of C-dots, and the carboxyl groups on C-dots are revealed for the first time as co-reactant sites for Ru(bpy) 3 2+-ECL. [Display omitted] Carbon nanodots (C-dots) with good biocompatibility have been extensively utilized as co-reactants for electrochemiluminescence (ECL) of the tris(2,2′-bipyridine)ruthenium(II) (Ru(bpy) 3 2+) system. However, the ECL intensity of this system is still relatively low and the mechanism of C-dots as co-reactants remains unclear, which greatly limits its further application in bio-analysis. In this work, we revealed that the carboxyl groups on C-dots are co-reactant sites for Ru(bpy) 3 2+ ECL by systematically investigating the contribution of carboxyl, hydroxyl and carbonyl groups on the surface of C-dots to the ECL intensity. Further treatment with hydrogen peroxide to increase the carboxyl-group content on C-dots resulted in a 10-fold increase in ECL intensity over the original Ru(bpy) 3 2+/C-dots system. This work provides new insights for the rational design of ECL systems with C-dots as co-reactants and offers new chances for further applications of C-dots in the field of ECL. [ABSTRACT FROM AUTHOR]

The creation of affordable, long-lasting, and effective electrocatalysts is a significant research issue in the area of water splitting. In this work, Ru-modified CoP x spearhead on nickel foam (Ru-CoP x /NF) is fabricated by simple hydrothermal, impregnation and subsequent low-temperature phosphorization process. The incorporation of Ru into the Co-P structure enables the effective reconstruction of the electronic coordination environment. The Ru-CoP x /NF catalyst performs well for hydrogen evolution reaction (HER), achieving a current density of 10 mA cm−2 with low overpotentials of 41 mV and outstanding stability in 1 M KOH. Furthermore, the produced CoP x /NF has low overpotential of 280 mV, allowing 10 mA cm−2 for the oxygen evolution reaction (OER) in 1 M KOH. In addition, the developed asymmetric Ru-CoP x /NF||CoP x /NF electrolyzer could drive 10 mA cm−2 in alkaline electrolyte with a low cell voltage of 1.51 V. Surprisingly, water-splitting may be efficiently by renewable energy sources, presenting a viable strategy for lowering the cost of creating hydrogen energy. The synthesized Ru-CoP x /NF exhibits excellent electrocatalytic performance for HER, with low overpotentials of 41, 73 and 168 mV, driving 10 mA cm−2 in alkaline, acidic and neutral media, respectively. The synthesized CoP x /NF without Ru has excellent OER performance, with an overpotential of only 280 mV@10 mA cm−2. The Ru-CoP x /NF||CoP x /NF electrolyzer can be powered by sustainable energies. [Display omitted] • The spearhead-like nanostructures provide abundant active sites. • The introduction of Ru optimized the reaction kinetics for HER. • The prepared catalysts exhibit excellent catalytic performance for HER and OER. [ABSTRACT FROM AUTHOR]

By rationally adjusting the coordination environment and constructing the more electron‐enriched active site in single‐atom catalysts, the effect of heterogenous peroxymonosulfate (PMS)‐based Fenton‐like reactions can be effectively improved, yet remains a severe challenge. In this study, the electron‐rich Ru dual‐atom site is successfully immobilized onto N‐doped carbon (Ru2N6‐C) for PMS activation in water purification. The presence of electron‐rich Ru dual‐atom sites not only provides more electrons for PMS but also facilitates the formation of a Yeager adsorption configuration on the catalyst surface, which enhances O─O bond cleavage and leads to an increase in •SO4− and •OH generation. Moreover, the Ru2N6‐C catalyst exhibits exceptional durability and reliability, achieving an ultra‐high efficiency with a turnover frequency of 153.95 min−1 M−1 for the naproxen degradation. A membrane reactor is further developed for the purification of wastewater, which is expected to provide a viable approach to controlling water pollution through the design of metal dual‐atom sites carbon‐based catalysts. [ABSTRACT FROM AUTHOR]

The efficient decomposition of ammonia to produce COx‐free hydrogen at low temperatures has been extensively investigated as a potential method for supplying hydrogen to mobile devices based on fuel cells. In this study, we employed dielectric barrier discharge (DBD) plasma, a non‐thermal plasma, to enhance the catalytic ammonia decomposition over supported Ru catalysts (Ru/Y2O3, Ru/La2O3, Ru/CeO2 and Ru/SiO2). The plasma‐catalytic reactivity of Ru/La2O3 was found to be superior to that of the other three catalysts. It was observed that both the physicochemical properties of the catalyst (such as support acidity) and the plasma discharge behaviours exerted significant influence on plasma‐catalytic reactivity. Combining plasma with a Ru catalyst significantly enhanced ammonia conversion at low temperatures, achieving near complete NH3 conversion over the 1.5 %‐Ru/La2O3 catalyst at temperatures as low as 380 °C. Under a weight gas hourly space velocity of 2400 mL gcat−1 h−1 and an AC supply power of 20 W, the H2 formation rate and energy efficiency achieved were 10.7 mol gRu−1 h−1 and 535 mol gRu−1 (kWh)−1, respectively, using a 1.5 %‐Ru/La2O3 catalyst. [ABSTRACT FROM AUTHOR]

The in-situ activation process alleviates the strong ruthenium-hydrogen and ruthenium-hydroxyl bonds, optimizing hydrogen and hydroxyl desorption energy. [Display omitted] • Partially oxidized Ru nanoparticles dispersed Ni 3 N nanosheet electrocatalyst was developed. • The in-situ electrochemical activation effectively promoted hydrogen evolution. • The controlled oxidation alleviates the strong Ru-H and Ru-OH bonds. • The catalysts show superior performance for HER and urea-assisted water splitting. The rational design of electrocatalysts with exceptional performance and durability for hydrogen production in alkaline medium is a formidable challenge. In this study, we have developed in-situ activated ruthenium nanoparticles dispersed on Ni 3 N nanosheets, forming a bifunctional electrocatalyst for hydrogen evolution and urea oxidation. The results of experimental analysis and theoretical calculations reveal that the enhanced hydrogen evolution reaction (HER) performance of O-Ru-Ni 3 N stems primarily from the optimized hydrogen adsorption and hydroxyl adsorption on Ru sites. The O-Ru-Ni 3 N on nickel foam (NF) electrode exhibits excellent HER performance, requiring only 29 mV to reach 10 mA cm−2 in an alkaline medium. Notably, when this O-Ru-Ni 3 N/NF catalyst is employed for both HER and urea oxidation reaction (UOR) to create an integrated H 2 production system, a current density of 50 mA cm−2 can be generated at the cell voltage of 1.41 V. This report introduces an energy-efficient catalyst for hydrogen production and proposes a viable strategy for anodic activation in energy chemistry. [ABSTRACT FROM AUTHOR]

The catalytic alkoxycarbonylation of alkenes is an attractive, atom‐efficient method for producing value‐added carboxylic esters. However, the conventional catalyst system for this reaction needs coordination with a noble metal, sensitive ligands and proton acid additives. Therefore, the design of a simple and efficient catalyst system without any acid additives under mild conditions is still a major challenge. In this work, a simple ruthenium/deep eutectic solvent catalytic system was developed to effectively catalyse the alkoxycarbonylation reaction without any sensitive ligands or acid additives under mild conditions. The conversion of 1‐hexene reached 99.0 %, and the ester selectivity was 99.1 %, much higher than that of Ruthenium carbonyl without deep eutectic solvent. The excellent performance of the catalytic system could be ascribed to the form of the ruthenium active species [Ru(CO)2Br3]− in the deep eutectic solvent. This innovative catalyst system presents a significant advancement in the alkoxycarbonylation reaction, eliminating the use of acid additives and delicate ligands. [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]

Green hydrogen production through the electrocatalytic hydrogen evolution reaction (HER) is a promising solution for transition from fossil fuels to renewable energy. To enable the use of a variety of electrolytes with different pH values, HER catalysts with pH universality are highly desirable but their performance remains mediocre. Herein, a pH‐universal HER catalyst composed of ruthenium nanoparticles decorated on amorphous Ni‐doped MoO3 (a–Ni–MoO3) nanowire support is reported, that is, Ru/a–Ni–MoO3, which achieves enhanced performance as compared to the commercial Ru/C catalyst. Electron transfer from Ru to a–Ni–MoO3 is identified by spectroscopic techniques, which results in a modified electronic structure of the Ru active sites with a reduced electron density of 4d states near the Fermi level. Density functional theory calculations further reveal that the modulated electronic structure weakens the interactions between the Ru active sites and the reaction intermediates, which facilitates the HER reaction steps including H intermediate desorption and water dissociation. Experimental and theoretical findings provide insight into enhancing pH‐universal HER performance through modulation of electrocatalyst electronic structure. [ABSTRACT FROM AUTHOR]

The worldwide demand for clean water is rising worldwide, yet wastewater decontamination is actually limited by the presence of refractory organic and inorganic compounds, calling for more efficient treatment methods. Here we review the use of ruthenium-based catalysts for the removal or transformation of pollutants at a concentration range of 1.0–100 mg/L under acid or neutral conditions. We focus on catalytic oxidation and reduction, and on the environmental impact of ruthenium catalysts. We discuss electrooxidation, photocatalytic oxidation, activation of inert oxidants, hydrogen-assisted reduction, electroreduction, and N–O bond activation. [ABSTRACT FROM AUTHOR]

The stable activity of catalysts is an important characteristic, which determines their suitability for industrial applications. The purpose of this study was to investigate the stability of ruthenium systems deposited on carbon under conditions simulating long-term operation in CO methanation. Two series of Ru/carbon catalysts were prepared and studied during CO methanation in a hydrogen-rich gas stream. Two graphitized carbons substantially differing in their surface area (23 and 1457 m2/g) were used as supports, and Ru loadings of 3 and 6 wt.% were applied. The stability of Ru/C catalysts was examined in a 240 h time-on-stream test. The samples were characterized by CO chemisorption, XRD, TEM, Raman spectroscopy, TG–MS studies and CO-TPD. The stability of the catalysts over 240 h in the CO + H2 mixture depended on the support type and Ru loading. The highest CO conversion and increased activity was observed for both catalysts with Ru dispersion above 80%. The tested systems were also resistant to carbon deposition. Interestingly, a similar level of activity was obtained for 3 wt.% Ru supported on the low surface area carbon. It is presumed that the similar activity observed for systems with such different ruthenium dispersion is related to the presence of active sites of different strength and structure on the surface of both small and large Ru particles. [ABSTRACT FROM AUTHOR]

Hydrogen has emerged as an important candidate for clean energy, owing to its environmentally friendly advantages. Electrolytic hydrogen production stands out as the most promising technology for hydrogen production. Therefore, the design of highly efficient electrocatalysts is significant to drive the application of hydrogen technologies. Platinum (Pt)-based catalysts are famous for their outstanding performance in the hydrogen evolution reaction (HER). However, the expensive cost limits its wide application. Ruthenium (Ru)-based catalysts have received extensive attention due to their relatively lower cost and HER performance similar to that of Pt. Nevertheless, the performance of Ru-based catalysts is still unable to meet industrial demands. Therefore, improving HER performance through the modification of Ru-based catalysts remains significant. In this review, the reaction mechanism of HER is analyzed and the latest research progress in the modification of Ru-based electrocatalysts is summarized. From the reaction mechanism perspective, addressing the adsorption of intermediates on the Ru-based electrocatalyst surface, the adsorption–activation of interface water molecules, and the behavior of interface water molecules and proposing solutions to enhance performance of Ru-based electrocatalyst are the main findings, ultimately contributing to promoting their application in the field of electrocatalysis. [ABSTRACT FROM AUTHOR]