Electron-rich Ru Research Articles

Constructing Electron-Rich Ru Clusters on Non-Stoichiometric Copper Hydroxide for Superior Biocatalytic ROS Scavenging to Treat Inflammatory Spinal Cord Injury.

Traumatic spinal cord injury (SCI) represents a complex neuropathological challenge that significantly impacts the well-being of affected individuals. The quest for efficacious antioxidant and anti-inflammatory therapies is both a compelling necessity and a formidable challenge. Here, in this work, the innovative synthesis of electron-rich Ru clusters on non-stoichiometric copper hydroxide that contain oxygen vacancy defects (Ru/def-Cu(OH)2), which can function as a biocatalytic reactive oxygen species (ROS) scavenger for efficiently suppressing the inflammatory cascade reactions and modulating the endogenous microenvironments in SCI, is introduced. The studies reveal that the unique oxygen vacancies promote electron redistribution and amplify electron accumulation at Ru clusters, thus enhancing the catalytic activity of Ru/def-Cu(OH)2 in multielectron reactions involving oxygen-containing intermediates. These advancements endow the Ru/def-Cu(OH)2 with the capacity to mitigate ROS-mediated neuronal death and to foster a reparative microenvironment by dampening inflammatory macrophage responses, meanwhile concurrently stimulating the activity of neural stem cells, anti-inflammatory macrophages, and oligodendrocytes. Consequently, this results in a robust reparative effect on traumatic SCI. It is posited that the synthesized Ru/def-Cu(OH)2 exhibits unprecedented biocatalytic properties, offering a promising strategy to develop ROS-scavenging and anti-inflammatory materials for the management of traumatic SCI and a spectrum of other diseases associated with oxidative stress.

Oxygen vacancies promoted hydrogen production from methanol aqueous phase reforming over MgAl−LDHs supported plasmonic Ru nanoparticles catalyst

Catalytic aqueous phase reforming of methanol is a promising process for the sustainable hydrogen production. The search for highly efficient heterogeneous catalyst is a topic of interest. Herein, we report oxygen vacancies enriched MgAl−LDHs supported plasmonic Ru nanoparticles catalyst exhibit excellent photocatalytic performance for efficient hydrogen production at 150 ºC under light irradiation. Characterizations demonstrate abundant oxygen vacancies are introduced into MgAl−LDHs via “memory effect”. The local electron transfer from oxygen vacancies of the MgAl−LDHs to the Ru nanoparticles leading the formation of electron-rich Ru species, which promote the dehydrogenation of methanol under light irradiation. In situ DRIFTS demonstrated a redox mechanism of water-gas shift reaction due to the existence of oxygen vacancies, which resulted a faster hydrogen production rate. This work displays a facile strategy for synthesis of oxygen vacancies rich LDH supported metal nanoparticles catalysts and deep understanding into the pathway and mechanism toward the effective hydrogen production.

S-S Bond Strategy at Sulfide Heterointerface: Reversing Charge Transfer and Constructing Hydrogen Spillover for Boosted Hydrogen Evolution.

Developing efficient electrocatalyst in sulfides for hydrogen evolution reaction (HER) still poses challenges due to the lack of understanding the role of sulfide heterointerface. Here, we report a sulfide heterostructure RuSx/NbS2, which is composed of 3R-type NbS2 loaded by amorphous RuSx nanoparticles with S-S bonds formed at the interface. As HER electrocatalyst, the RuSx/NbS2 shows remarkable low overpotential of 38 mV to drive a current density of 10 mA cm-2 in acid, and also low Tafel slope of 51.05 mV dec-1. The intrinsic activity of RuSx/NbS2 is much higher than that of Ru/NbS2 reference as well as the commercial Pt/C. Both experiments and theoretical calculations unveil a reversed charge transfer at the interface from NbS2 to RuSx that driven by the formation of S-S bonds, resulting in electron-rich Ru configuration for strong hydrogen adsorption. Meanwhile, electronic redistribution induced by the sulfide heterostructure facilitates hydrogen spillover (HSo) effect in this system, leading to accelerated hydrogen desorption at the basal plane of NbS2. This study provides an effective S-S bond strategy in sulfide heterostructure to synergistically modulate the charge transfer and adsorption thermodynamics, which is very valuable for the development of efficient electrocatalysts in practical applications.

Oxidation of 5-Hydroxymethylfurfural into 2,5-Diformylfuran on Alkali Doped Ru/C Catalysts. Electron Properties of Ruthenium Species as Descriptor of Catalytic Activity.

Selective aerobic oxidation of 5-hydroxymethylfurfural into 2,5-diformylfuran has been achieved on alkali doped Ru/C catalyst. Optimization of Ru metal nanoparticles, as well as the nature and amount of the alkali dopant have been performed. The results showed that doping the Ru/C catalyst with controlled amount of potassium increases the catalytic activity, 2.5 fold with respect to the non-doped sample. Spectroscopic studies showed that these differences in activity can be attributed to a different oxidation reaction mechanism associated to the presence of electron rich Ru species in the promoted sample that facilitate the dissociation of O2, while prevents the oxidation of the metal. The Ru/C-K doped catalyst resulted very stable against leaching and metal sintering, being possible the reuse over several consecutive runs. Moreover, the catalyst could be successfully applied to the oxidation of different alcohols.

Electrodeposition strategies for synthetic highly dispersed Ru-decorated Co(OH)2 nanoneedles as advanced hydrogen evolution reaction catalysts

Ru-based nanomaterials have a lot of potential as electrochemical hydrogen evolution reaction (HER) catalysts; however, achieving a uniform dispersion of Ru nanoparticles on substrate materials remains a key challenge. To achieve this, in the current study, we formed NF/Co(OH)2/Ru by electrodepositing Ru nanoparticles onto Co(OH)2 nanoneedles. The Co and O vacancies in the sample promoted water decomposition and the cleavage of O-H bonds, while the high surface energies at the apexes of the Co(OH)2 nanoneedles supported the even growth and attachment of Ru nanoparticles. In addition, the electron-rich Ru nanoparticles aided in the desorption of hydrogen intermediates. Compared to recently published Ru-based HER materials, the NF/Co(OH)2/Ru material created in this study shown improved electrochemical characteristics, with an overpotential of 20 mV at 10 mA·cm−2 and a Tafel slope of 35.43 mV·dec−1. Therefore, this material and the findings of this study are expected to contribute to HER research.

Selective CO2 Photoreduction into CH4 Triggered by the Synergy between Oxygen Vacancy and Ru Substitution under Near-Infrared Light Irradiation.

Near-infrared (NIR) light powdered CO2 photoreduction reaction is generally restricted to the separation efficiency of photogenerated carriers and the supply of active hydrogen (*H). Herein, the study reports a retrofitting hydrogenated MoO3-x (H-MoO3-x) nanosheet photocatalysts with Ru single atom substitution (Ru@H-MoO3-x) fabricated by one-step solvothermal method. Experiments together with theoretical calculations demonstrate that the synergistic effect of Ru substitution and oxygen vacancy can not only inhibit the recombination of photogenerated carriers, but also facilitate the CO2 adsorption/activation as well as the supply of *H. Compared with H-MoO3-x, the Ru@H-MoO3-x exhibit more favorable formation of *CHO in the process of *CO conversion due to the fast *H generation on electron-rich Ru sites and transfer to *CO intermediates, leading to the preferential photoreduction of CO2 to CH4 with high selectivity. The optimized Ru@H-MoO3-x exhibits a superior CO2 photoreduction activity with CH4 evolution rate of 111.6 and 39.0µmol gcatalyst -1 under full spectrum and NIR light irradiation, respectively, which is 8.8 and 15.0 times much higher than that of H-MoO3-x. This work provides an in-depth understanding at the atomic level on the design of NIR responsive photocatalyst for achieving the goal of carbon neutrality.

Cu-mediated electron-rich Ru centers on metal carbides for highly efficient hydrogen production from seawater

Seawater splitting for hydrogen production provides a promising pathway for green energy systems. However, the sluggish kinetics, corrosive ions, and the calcareous deposit seriously impede the wide-scale application of seawater electrolysis. Here, we report a trace amount of Cu-mediated anchoring electron-rich Ru centers on metal carbides (Cu-Ru/WC@C) for efficient hydrogen evolution from corrosive seawater. Benefiting from the conductive, electron-loss, and protophilic capacities of Cu atoms, the created Cu-Ru/WC@C catalyst possesses an electron-rich, anti-corrosive, and low oxophilic microenvironments, which eventually delivers excellent hydrogen evolution activities and anti-corrosion properties in seawater electrolysis. It requires a low overpotential of 392 mV to reach 1 A cm−2 and good long-term stability in alkaline seawater. Notably, the membrane electrolyzer with Cu-Ru/WC@C cathode exhibits outstanding performances for continuous H2 production under 1.875 V with 250 mA cm−2. This approach provides essential insights into the seawater corrosion resistance for cathode materials that match the electrochemical hydrogen production industry.

Selective Hydrodeoxygenation of Lignin-Derived Phenolic Monomers to Cyclohexanol over Tungstated Zirconia Supported Ruthenium Catalysts.

The selective hydrodeoxygenation (HDO) of lignin-derived methoxyphenols to cyclohexanol is one of the most significant transformation in biomass conversion since cyclohexanol is an important industrial raw material. This study has disclosed a series of tungstated zirconia with different Zr/W ratio supported Ru catalysts (Ru/xZrW, x means the molar ration of Zr/W) for the hydrodeoxygenation (HDO) of guaiacol to cyclohexanol. Among these catalysts, Ru/16ZrW has the best catalytic activity, which can achieve 92 % yield of cyclohexanol under the conditions of 180 °C and 1 MPa H2 pressure for 2 h (TOF 231 h-1). Compared with Ru/ZrO2, Ru/16ZrW has smaller particles, more dispersed and electron-rich Ru species, significant hydrogen spillover and more acid sites, which are the main reason for its excellent performance on this reaction. Apart from guaiacol, other methoxy substitution phenols and organosolv lignin can also be converted into cyclohexanol via hydrodeoxygenation reactions over this catalyst.

V-doped activated Ru/Ti2.5V0.5C2 dual-active center accelerate hydrogen production from ammonia borane

Designing and constructing the active center of Ru-based catalysts is the key to efficient hydrolysis of ammonia borane (NH3BH3, AB) for hydrogen production. Herein, V-doped Ru/Ti2.5V0.5C2 dual-active center catalysts were synthesized, showing excellent catalytic ability for AB hydrolysis. The corresponding turnover frequency value was 1072 min−1 at 298 K, and the hydrolysis rate rB of AB was 235 × 103 mL·min−1·gRu–1. X-ray photoelectron spectroscopy results indicated that the interaction between V-doped Ti3C2 and catalytic metal Ru transfers electrons from Ti to Ru, resulting in electron-rich Ru species. According to density functional theory calculations, the activation energy and reaction dissociation energy of the reactants AB and H2O on V-doped catalysts were lower than those of Ru/Ti3C2, thus optimizing the catalytic kinetics of AB hydrolysis. The modification strategy of V-doped Ti3C2 provides a new pathway for the development of high-performance catalysts for AB hydrolysis.

Electron-Rich Ru Supported on N-Doped Coffee Biochar for Selective Reductive Amination of Furfural to Furfurylamine.

Highly selective synthesis of primary amines from renewable biomass has attracted increasing attention, but it still faces great challenges in chemical industry applications. In this study, an electron-rich Ru catalyst was constructed by doping N into coffee biochar using a one-pot carbonization method (Ru/NCB-600). Ru/NCB-600 showed high catalytic activity and yield for the reductive amination of furfural with green and cheap NH3 and H2. The excellent catalytic performance of Ru/NCB-600 was closely correlated to the formation of electron-rich Ruδ- species (Ruδ--Nxδ+), which endowed Ru/NCB-600 with an enhanced H2 adsorption and activation ability. Ru/NCB-600 showed a high formation rate of 95.6 gfurfurylamine·gRu-1·h-1 and a high yield of furfurylamine (98.6%) at 50 °C. Ru/NCB-600 can also be used for the reductive amination of various carbonyl compounds in good to excellent yield (95.4-99%). This study thus provides a potential pathway for the highly selective reductive amination of carbonyl compounds by regulating the electron density of Ru.

Polarized Ultrathin BN Induced Dynamic Electron Interactions for Enhancing Acidic Oxygen Evolution.

Developing ruthenium-based heterogeneous catalysts with an efficient and stable interface is essential for enhanced acidic oxygen evolution reaction (OER). Herein, we report a defect-rich ultrathin boron nitride nanosheet support with relatively independent electron donor and acceptor sites, which serves as an electron reservoir and receiving station for RuO2, realizing the rapid supply and reception of electrons. Through precisely controlling the reaction interface, a low OER overpotential of only 180 mV (at 10 mA cm-2) and long-term operational stability (350 h) are achieved, suggesting potential practical applications. In situ characterization and theoretical calculations have validated the existence of a localized electronic recycling between RuO2 and ultrathin BN nanosheets (BNNS). The electron-rich Ru sites accelerate the adsorption of water molecules and the dissociation of intermediates, while the interconnection between the O-terminal and B-terminal edge establishes electronic back-donation, effectively suppressing the over-oxidation of lattice oxygen. This study provides a new perspective for constructing a stable and highly active catalytic interface.

Kinetically promoted hydrogen generation by Ru nanoparticles decorated CoB2O4 on mesoporous carbon spheres with rich oxygen vacancies for NaBH4 hydrolysis

Developing heterostructured catalysts with highly active and reusable is an urgent task to achieve green hydrogen production via NaBH4. Herein, we proposed a novel NaCl template method, which involves solid-state physical grinding of metal salts, reducing agents and prepared carbon spheres with the participation of sodium chloride to synthesize Ru-particles decorated CoB2O4 supported on hollow mesoporous carbon nanospheres (Ru/CoB2O4@C) catalysts for efficient and durable H2 generation through alkaline hydrolysis of NaBH4. The optimized catalyst with a Ru content of 3.0 wt% exhibits a high hydrogen generation rate of 8139 mL min−1gcat-1 and a low activation energy of 33.2 kJ mol−1 for NaBH4 hydrolysis, which is one of the most efficient catalysts reported recently. The extraordinary performance is mainly attributed to the synergistic effect between Ru and CoB2O4 species and abundant oxygen vacancies, which facilitate charge redistribution and provide more active sites, thereby enhancing the catalytic activity. Density functional theory calculations support the proposed Michaelis-Menten mechanism, where BH4− and H2O are adsorbed on electron-rich Ru and electron-deficient CoB2O4 surfaces, respectively, and the reaction energy barrier for the rupture of the B-H bond as the rate-determining step is only 1.37 eV, synergistically promoting the hydrolysis of NaBH4. Our study provides an innovative method for designing efficient and stable catalysts for green hydrogen generation.

Ru incorporated into Se vacancy-containing CoSe2 as an efficient electrocatalyst for alkaline hydrogen evolution.

In alkaline media, slow water dissociation leads to poor overall hydrogen evolution performance. However, Ru catalysts have a certain water dissociation performance, thus regulating the Ru-H bond through vacancy engineering and accelerating water dissociation. Herein, an excellent Ru-based electrocatalyst for the alkaline HER has been developed by incorporating Ru into Se vacancy-containing CoSe2 (Ru-VSe-CoSe2). The results from X-ray photoelectron spectroscopy, kinetic isotope effect, and cyanide poisoning experiments for four catalysts (namely Ru-VSe-CoSe2, Ru-CoSe2, VSe-CoSe2, and CoSe2) reveal that Ru is the main active site in Ru-VSe-CoSe2 and the presence of Se vacancies greatly facilitates electron transfer from Co to Ru via a bridging Se atom. Thus, electron-rich Ru is formed to optimize the adsorption strength between the active site and H*, and ultimately facilitates the whole alkaline HER process. Consequently, Ru-VSe-CoSe2 exhibits an excellent HER activity with an ultrahigh mass activity of 44.2 A mgRu-1 (20% PtC exhibits only 3 A mgRu-1) and a much lower overpotential (29 mV at 10 mA cm-2) compared to Ru-CoSe2 (75 mV), VSe-CoSe2 (167 mV), CoSe2 (190 mV), and commercial Pt/C (41 mV). In addition, the practical application of Ru-VSe-CoSe2 is illustrated by designing a Zn-H2O alkaline battery with Ru-VSe-CoSe2 as the cathode catalyst, and this battery shows its potential application with a maximum power density of 4.9 mW cm-2 and can work continuously for over 10 h at 10 mA cm-2 without an obvious decay in voltage.

Manipulating the interfacial water structure by electron redistribution for the hydrogen evolution reaction.

The sluggish dissociation of water in alkaline electrolytes significantly hinders the kinetics of the hydrogen evolution reaction (HER), particularly on surfaces of Ru-based catalysts. The structure of water at the water-catalyst interface influences this dissociation process, yet controlling the configuration of water molecules is challenging due to their random distribution. In this study, a NiRu alloy supported on nitrogen-doped carbon (NiRu/NC) is selected as a model catalyst to investigate the electron distribution of the catalyst manipulating the adsorption configuration and orientation of water molecules. The introduction of Ni leads to charge transfer from Ni to Ru atoms within the NiRu alloy, causing a notable redistribution of charge that strengthens the local electric fields surrounding the NiRu alloy. These electron-rich Ru sites attract K+ cations to the surface, resulting in an increased presence of K+ cation-hydrated water molecules, which is an H-down configuration with a reduced Ru-H distance. This phenomenon is confirmed by in situ Raman spectroscopy. Consequently, NiRu/NC exhibits outstanding HER performance, achieving low overpotentials of 16 and 344 mV at current densities of 10 and 1000 mA cm-2, respectively.

Selective hydrogenation of levulinic acid at room temperature: Boosting ruthenium nanoparticle efficiency via coupling with in-situ pyridinic-N-doped carbon nanoflowers

Integrating unique morphology and tunable electronic state of supported metallic catalysts via one-step is an attractive pathway to boost their catalytic behaviors in selective hydrogenation reactions. Here, electronic state-tunable Ru nanoparticles (NPs) coupled with three-dimensional (3D) hierarchical carbon nanoflowers with in-situ generated pyridinic-nitrogen (Ru/PNC) are devised. Combining with systematical characterizations, kinetics investigations, and density functional theory (DFT) computations, the pyridinic-N species is proved to facilitate the formation of electron-rich Ru, which insures the weaker adsorption of levulinic acid but stronger adsorption of H2 molecules on Ru, ultimately reducing the apparent activation energy of selective hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL). As a result, a high turnover frequency (TOF) of 5042.5 h−1 and a GVL selectivity of > 99% are achieved on the most electron-rich Ru/PNC catalyst. A positive linearity between the TOFs and the surface pyridinic-N/Ru0 ratios is recognized, further corroborating the electron-rich Ru-mediated intrinsic activity enhancement evoked by the surface pyridinic-N species on carbon nanoflowers.

Superhydrophilic and superaerophobic Ru-loaded NiCo bimetallic hydroxide achieves efficient hydrogen evolution over all pH ranges.

Realizing an effective, binder-free, and super-wetting electrocatalyst for the hydrogen evolution reaction (HER) at full pH is essential for the creation of clean hydrogen. In this study, the Ru-loaded NiCo bimetallic hydroxide (Ru@NiCo-BH) catalyst was prepared by spontaneous redox reaction. The chemical interaction between Ru NPs and NiCo-BH by the Ru-O-M (M=Ni, Co) interface bond, the electron-rich Ru active site, and the multi-channel nickel foam carrier make the superhydrophilic and superaerophobic surface advantageous for mass transfer in the HER process. Therefore, Ru@NiCo-BH has remarkable HER activity, with low overpotential of 29, 68and 80 mV, and 10 mA cm-2 current density can be obtained in alkaline, neutral and acidic electrolytes respectively. This work provides a reference for the rational development of universal electrocatalysts for hydrogen evolution in the all pH ranges through simple design strategies.

Cyano group modified graphitic carbon nitride supported Ru nanoparticles for enhanced CO2 methanation

Graphitic carbon nitride (g-C3N4) based materials has been widely used for catalytic CO2 hydrogenation reaction. However, the catalytic activity is restricted due to the barren active sites and the weak ability to activate CO2 for the traditional g-C3N4. We demonstrate here that cyano group modified g-C3N4 supported Ru nanoparticles exhibits high activity and selectivity for CO2 methanation. The introduction of cyano group promotes the formation of medium basic sites for enhanced CO2 adsorption. Meanwhile, the formation of electron-rich Ru nanoparticles with the assistance of cyano group boosts the H2 activation. The synergistic effect of cyano group and Ru nanoparticles improves catalytic performance up to 14 times. Characterizations prove that cyano group with electron-withdrawing properties influences the way of CO2 adsorption via electron transfer and changes the CO2 hydrogenation reaction pathway. This work provides a new insight into the switching of CO2 hydrogenation pathway and enhanced catalytic activity via surface functional groups modification of g-C3N4 based catalyst.

Modulating the interfacial built-in electric field in oxygen vacancies-enriched Ru/MxOy@C (M = V, Nb, Ta) ordered macroporous heterojunctions for electrocatalytic hydrogen production

The differences in Fermi levels (Ef) can drive the electrons flow across the metal/semiconductor interfaces, resulting in a built-in electric field (BEF) to enhance charge migration. Meanwhile, the induced electron-rich/deficient counterparts can modulate the active sites and reaction steps. In this work, a three-dimensionally ordered macroporous (3DOM) heterostructure with oxygen vacancy (Ov) supported by carbon (Ru/MxOy@C, M = V, Nb, Ta) was fabricated. Since the Ef of MxOy is higher than that of Ru, an adjustable BEF directed by MxOy towards Ru is generated at the interface. The electron-deficient MxOy can dissociate H2O effectively, and the electron-rich Ru favors the desorption of hydrogen intermediates. Both experimental and theoretical results confirm the above conclusions. The Ru/Ta2O5@C demonstrates superior activity than Pt/C. This work provides new design principles toward efficient electrocatalysts for hydrogen evolution reaction (HER).

Defect-rich ruthenium dioxide electrocatalyst enabled by electronic reservoir effect of carbonized polymer dot for remarkable pH-universal oxygen evolution

Designing highly active and durable electrocatalysts for oxygen evolution reaction (OER) over a wide pH range is of great significance, but it remains challenging. Herein, a defect-rich RuO2 electrocatalyst with pH-universal OER activity is developed by rationally utilizing the electronic reservoir effect of Mn-coordinated carbonized polymer dots (Mn-CPDs). Mn-CPDs as distinct electron acceptor/donor endows Ru-O sites of RuO2 with abundant defective structures (i.e., O-Ru-O-Ru-Ru sites and O-Ru-O-Mn units) via reduction-oxidation processes, with incorporated Mn atoms simultaneously feeding electron to Ru. The resultant Ru-O-Mn/CPD exhibits an ultralow OER potential of 196 mV, 194 mV and 251 mV at 10 mA·cm−2 under 0.5 M H2SO4, 1.0 M KOH, and 1.0 M PBS media, respectively, and long-term catalytic stability, which are among the best OER electrocatalysts. Surprisingly, Ru-O-Mn/CPD also shows great Pt-like hydrogen evolution activity. The theoretical simulation indicates that defective Ru-O-Mn structures produce electron-rich Ru region and near-optimal Ru-4d/O-2p band center, thus optimizing the adsorption/desorption kinetics of key intermediates.

Constructing Ru particles decorated Co3B-CoP heterostructures as a highly active and reusable catalyst for H2 generation by catalyzing NaBH4 hydrolysis

Constructing an efficient and reusable catalyst for catalyzing NaBH4 hydrolysis for H2 production is of vital significance. Herein, the Ru particles decorated Co3B-CoP heterostructures are obtained by chemical reduction and gas-phase phosphating treatment. The strong electronic interaction and abundant heterojunctions between the Co3B-CoP substrate and Ru particles have been elucidated. The optimal Ru0.063/Co3B-CoP catalyst exhibits a fast hydrogen generation rate (8875.8 mL min−1 gcat−1) and a high turnover frequency (636.0 min−1) at 25 °C, superior to most ever reported catalysts. The excellent NaBH4 hydrolysis performance can be attributed to the lower activation energy (47.6 kJ mol−1) and the synergy between Co3B-CoP substrate and Ru particles. Density functional theory calculations show that electrons penetrate into Ru particles from Co3B-CoP substrate, in which the electron-rich Ru particles can selectively adsorb BH4− ions, while the electron-deficient Co3B-CoP facilitates the capture of H2O molecules, thereby synergistically promote the catalyzing NaBH4 hydrolysis to produce H2.