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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]

To solve the problem of low N 2 selectivity of Ru/Ce/ZrO 2 (R/C/Z) catalysts in NH 3 selective catalytic oxidation (NH 3 -SCO) reaction, herein ZrO 2 supports were treated with sulfuric acid and its effects on NH 3 -SCO performance were investigated systematically. The results showed that Ru/Ce/ZrO 2 -10S (R/C/Z-10S) catalyst, in which the mass ratio of sulfuric acid to ZrO 2 was 10 %, exhibited N 2 selectivity of 95.7 % at 350 °C, that was significantly higher than R/C/Z catalyst (57.8 %). NH 3 -TPD tests indicated that sulfate treatment of ZrO 2 supports in R/C/Z catalysts led to more abundant acidic sites on catalyst surface, which was in favor of enhancing NH 3 adsorption capacity remarkably. But when mass ratio of sulfuric acid to ZrO 2 increased up to 20 %, an aggregation of metal oxides on the surface of R/C/Z-20S catalyst could be observed clearly, which might impose an adverse impact on NH 3 -SCO performance. In-situ DRIFTS results revealed that, compared to R/C/Z catalyst, there were much more Brönsted acid sites on the surface of R/C/Z-10S catalyst, and the corresponding NH 3 species on acidic sites could be consumed quickly in intermediate reactions. More importantly, amide (-NH 2) species rather than imide (-NH) and nitrosyl (-HNO) species, were the majority on the surface of R/C/Z-10S catalyst, implying that there might be a suppressing effect on further dehydrogenation of -NH 2 species into -NH species owning to sulfate treatment of ZrO 2 supports in R/C/Z catalysts. Therefore, internal selective catalytic reduction (i-SCR) mechanism rather than -NH mechanism played a vital role in NH 3 -SCO reaction over R/C/Z-10S catalyst. [Display omitted] • Surface acidity of Ru/Ce/ZrO 2 catalysts was tuned by treatment of ZrO 2 support with sulfuric acid. • Ru/Ce/ZrO 2 -10S catalyst exhibited significantly higher N 2 selectivity compared to Ru/Ce/ZrO 2 catalyst. • Ru/Ce/ZrO 2 -10S catalyst followed internal selective catalytic reduction (i-SCR) and imide (-NH) mechanisms. • NH 3 -SCO reaction over Ru/Ce/ZrO 2 -10S catalyst were dominated by i-SCR mechanism rather than -NH mechanism. [ABSTRACT FROM AUTHOR]

Corneal collagen crosslinking (CXL) is a commonly used minimally invasive surgical technique to prevent the progression of corneal ectasias, such as keratoconus. Unfortunately, riboflavin/UV-A light-based CXL procedures have not been successfully applied to all patients, and result in frequent complications, such as corneal haze and endothelial damage. We propose a new method for corneal crosslinking by using a Ruthenium (Ru) based water-soluble photoinitiator and visible light (430 nm). Tris(bipyridine)ruthenium(II) ([R u (bpy) 3 ]2+) and sodium persulfate (SPS) mixture covalently crosslinks free tyrosine, histidine, and lysine groups under visible light (400–450 nm), which prevents UV-A light-induced cytotoxicity in an efficient and time saving collagen crosslinking procedure. In this study, we investigated the effects of the Ru/visible blue light procedure on the viability and toxicity of human corneal epithelium, limbal, and stromal cells. Then bovine corneas crosslinked with ruthenium mixture and visible light were characterized, and their biomechanical properties were compared with the customized riboflavin/UV-A crosslinking approach in the clinics. Crosslinked corneas with a ruthenium-based CXL approach showed significantly higher young's modulus compared to riboflavin/UV-A light-based method applied to corneas. In addition, crosslinked corneas with both methods were characterized to evaluate the hydrodynamic behavior, optical transparency, and enzymatic resistance. In all biomechanical, biochemical, and optical tests used here, corneas that were crosslinked with ruthenium-based approach demonstrated better results than that of corneas crosslinked with riboflavin/ UV-A. This study is promising to be translated into a non-surgical therapy for all ectatic corneal pathologies as a result of mild conditions introduced here with visible light exposure and a nontoxic ruthenium-based photoinitiator to the cornea. Keratoconus, one of the most frequent corneal diseases, could be treated with riboflavin and ultraviolet light-based photo-crosslinking application to the cornea of the patients. Unfortunately, this method has irreversible side effects and cannot be applied to all keratoconus patients. In this study, we exploited the photoactivation behavior of an organoruthenium compound to achieve corneal crosslinking. Ruthenium-based organic complex under visible light demonstrated significantly better biocompatibility and superior biomechanical results than riboflavin and ultraviolet light application. This study promises to translate into a new fast, efficient non-surgical therapy option for all ectatic corneal pathologies. [Display omitted] [ABSTRACT FROM AUTHOR]

Creating useful chemicals or fuels from CO 2 is one of the most promising ways to reach carbon neutral. In this work, through the formation of Lewis acid sites, a string of boron-atom-coordinated Ru single-atom catalysts (SACs), namely RuB x N 4-x @TiN (x=0–4), were constructed, and their CO 2 reduction reaction (CO 2 RR) was systematically studied. The results show that o -RuB 2 N 2 @TiN, p -RuB 2 N 2 @TiN, and RuB 3 N 1 @TiN are able to efficiently inhibit the competitive hydrogen evolution reaction (HER) and activate CO 2 , with a potential-determining step lower than 0.7 eV and high selectivity for CH 4 generation. This work shows that the synergistic effect of B and Ru atoms are able to effectively improve the catalytic activity, which is expected to offer a possible tactic for the sensible creation of effective CO 2 RR catalysts. • Boron doped Ru single-atom catalysts, were constructed for investigating the reaction mechanism of CO 2 reduction. • Synergistic effect of B and Ru atoms effectively improves catalytic activity for CO 2 reduction. • The RuB x N 4- x @TiN (x=2–3) can activate CO 2 with low potential-determining step and high selectivity for CH 4 generation. [ABSTRACT FROM AUTHOR]

A small amount of ruthenium (Ru) was introduced into carbon supported nickel diselenide (NiSe2/C) through a simple microwave route to obtain Ru incorporated ternary catalyst Ru(NiSe2)/C. A comparative study was performed without and with the heat treatment to examine the crystal phases, microstructures, electrocatalytic activities and stabilities toward oxygen reduction reaction (ORR) for binary NiSe2/C and ternary Ru(NiSe2)/C. The results revealed that the half-wave potential (E1/2) of the best performed Ru(NiSe2)/C-400 reached 0.64 V with the overall loss of 5.6% in E1/2 after 1000 cycles in 0.1 mol·l−1 HClO4, showing the highly improved ORR activity and excellent stability as compared with those of the best performed NiSe2/C-350. When tested as a cathode catalyst in the H2/O2 single cell at 65 °C and ambient pressure, the open circuit potential and the maximum power density approached 0.78 V and 132 mW·cm−2, respectively. The achieved mass activity of 0.08 mA·(μg Ru)−1 at 0.75 V was comparable to that of Ru(CoSe2)/C-400 (0.09 mA·(μg Ru)−1 ). The simultaneous enhancement in the ORR activity and stability of Ru(NiSe2)/C in an acid electrolyte might be mainly contributed by a new stable (Ru, Ni)Se2 like structure. Furthermore, selenium evaporation and grain growth could be effectively prevented during the heat treatment by Ru incorporation. [ABSTRACT FROM AUTHOR]

Improving the intrinsic catalytic activity of NiFe layered double hydroxide (LDH), which is a benchmark electrocatalyst for oxygen evolution reaction (OER), is a significant challenge. In the present study, we doped ruthenium ions into NiFe LDH (Ru-NiFe LDH) to accelerate the OER kinetics. Electrochemical measurements of NiFe LDH and Ru-NiFe LDH at similar mass loadings showed that Ru-NiFe LDH demonstrated a higher OER activity than that of NiFe LDH. Ru-NiFe LDH only requires an overpotential of 246 mV at 10 mA cm-2 in alkaline media. This attributes to ruthenium doping primarily, which can promote the catalytic activity of Fe sites and boost the electronic interaction among the Ni, Fe, and Ru metals according to the theoretical calculations. Ru-NiFe LDH is stable during OER stability measurements, which was confirmed by structure and elemental analysis. These findings will provide a useful approach for promoting the intrinsic activity of multi-metallic (oxy) hydroxide electrocatalysts toward the OER. [ABSTRACT FROM AUTHOR]

• MOF-derived, Ru nanoparticles embedded alumina (Ru@Al 2 O 3) is in situ synthesized for the reductive amination of furfural toward difurfurylamine. • Ru@Al 2 O 3 achieves a high yield of difurfurylamine (92%) using borohydrides as the reducing agent. • Ru@Al 2 O 3 possesses a higher degree of Ru dispersion (i.e., smaller Ru nanoparticles) compared to Ru/Al 2 O 3 catalysts prepared by the conventional impregnation method. • Experiments and DFT calculations suggest the promotive role of methoxide in the reduction of secondary imine. Difurfurylamine (DiFAM) 2 2 DiFAM: difurfurylamine. is a valuable chemical used in pharmaceuticals or polymers, but an efficient synthesis is rarely reported. One such method involves the imination of furfural (FAL) 3 3 FAL: furfural. and furfurylamine (FAM) 4 4 FAM: furfurylamine. to form difurfurylimine (DiFIM), 5 5 DiFIM: difurfurylimine. followed by the hydrogenation of DiFIM to produce DiFAM. This process can be carried out effectively using Ru nanoparticles and borohydrides as catalyst and reducing agent, respectively. Understanding the mechanism of this reaction is crucial for designing similar systems in the future. The materials Ru@Al 2 O 3 and Ru/γ-Al 2 O 3 were synthesized via in situ synthesis and impregnation, respectively. Characterization was then performed to verify the physicochemical properties of the materials. The catalytic reaction was carried out in an 80 °C oil bath with stirring for 1 h. Simulations were performed using density functional theory (DFT). 6 6 DFT: density functional theory. Ru@Al 2 O 3 obtained from MIL-53-NH 2 (Ru, Al) demonstrated a higher dispersion of Ru NPs due to their interaction with the –NH 2 ligands on MIL-53-NH 2 (Al). Moreover, DFT calculations predicted that the methanolysis products of borohydrides could reduce the activation energy of the reaction by forming a stable transition state. These factors combined to yield an impressive ca. 92% of DiFAM and provide new insights for designing hydrogenation systems. [ABSTRACT FROM AUTHOR]

Considering the flexibility in the synthesis that allows the formation of materials with more than two metals, the present study reports the preparation of trimetallic layered double hydroxides (LDHs) having Al as structural tri-positive cation, Ti as photocatalytically active d0 transition metal and either Ni or Co as dipositive cation. In addition, these LDHs were used as precursors of the corresponding trimetallic mixed oxides (MO). LDH and MO materials in combination with Ru(bpy) 3 Cl 2 as photosensitizer and triethanolamine as sacrificial electron donor were used as catalysts for CO 2 reduction under solar light irradiation. A different product selectivity, either CH 4 for Ni-LDH or CO and H 2 for Co-MO, was observed with production rates for CH 4 or CO that are among the highest reported for these systems. The role of the inorganic materials in the photocatalytic process was supported by transient absorption spectroscopy that revealed the quenching of the Ru(bpy) 3 Cl 2 triplet excited state by Ni-LDH or Co-MO. An important finding was that the trimetallic Co-Ti-Al oxide with cobaltite structure is able to perform CO 2 reduction in spite that the reduction potential of its conduction band is not sufficient to perform the process, evidence by photoluminescence revealing the existence of an upper electronic state responsible for the reduction. These results show the interest in screening multimetallic materials in photocatalysis due to their improved performance and diverse properties. [Display omitted] • A series of trimetallic layered double hydroxide (LDH) having Al, Ti and either Ni or Co. • Calcination of LDH produces a mixed metal oxides (MOs) with maintaining the spherical morphology of the LDH precursors. • Different product selectivity is obtained depending on the cations present in the composition of the materials. • NiTiAl LDH shows an outstanding activity for CO 2 reduction to methane of 4.59 μmol/h, and a selectivity above 86%. [ABSTRACT FROM AUTHOR]

• Ru/Pr 2 O 3 was the most active of the tested oxide-supported Ru catalysts. • Kinetic analysis explained the reason for the remarkable activity of Ru/Pr 2 O 3. • Hydrogen poisoning of the Ru surface was retarded over Ru/Pr 2 O 3. • Ru/Pr 2 O 3 exhibited a high NH 3 synthesis rate, 64 mmol h−1 g−1, at 3.0 MPa and 400 °C. • The NH 3 synthesis rate was 45 mmol h−1 g−1 at 350 °C, 3.0 MPa, and H 2/ N 2 = 1/0.5. We investigated the kinetics of NH 3 synthesis over a catalyst consisting of low-crystalline Ru nano-layers supported on Pr 2 O 3. We determined the reaction orders with respect to N 2 , H 2 , and NH 3 at various temperatures and pressures over Ru/Pr 2 O 3 , as well as Ru/CeO 2 and Ru/MgO. The reaction orders with respect to N 2 were always almost unity for all the catalysts under all the reaction conditions, indicating that the rate-determining step was N N bond cleavage. In contrast, the reaction orders with respect to H 2 differed among the catalysts and decreased with increasing pressure and increased with increasing temperature. Under all conditions, the reaction order with respect to H 2 was largest over Ru/Pr 2 O 3 and smallest over Ru/MgO, indicating that hydrogen poisoning of the Ru surface was retarded to a greater extent over Ru/Pr 2 O 3 than over Ru/MgO. In agreement with the trends of the H 2 reaction orders, the NH 3 synthesis rates over Ru/Pr 2 O 3 at 400 °C rose drastically (64 mmol h−1 g−1) as the pressure was increased from 0.1 to 3.0 MPa. Furthermore, decreasing the feed gas H 2 /N 2 ratio at 3.0 MPa effectively increased the NH 3 synthesis rate over Ru/Pr 2 O 3 , which reached 45 mmol h−1 g−1 at 350 °C at a H 2 /N 2 ratio of 1/0.5. [ABSTRACT FROM AUTHOR]

Nowadays, ammonia is viewed as the prospective green hydrogen fuel carrier. Yet, there still is a demand for active, energy-efficient NH 3 synthesis catalysts to make ammonia use economically viable. This paper studies and discusses lanthanide oxide-supported cobalt catalysts for low-pressure ammonia synthesis, which are intended to be a model for prototyping systems alternative to ruthenium-based catalysts. In the Co/Ln 2 O 3 system, lanthanide oxide is a support and an electronic promoter. The electron density on the active phase's surface is increased through Strong Metal-Support Interactions and the formation of oxygen-deficient, Ln 2 O 3−x species capable of electron donation. In the systems, electronic promotion strength depends on the Ln3+ cation and the support conductivity, catalyst Turnover Frequency and basicity increase exponentially with the increase of the Ln3+ ionic radius. These dependencies enable the design of novel cobalt catalysts of specific properties and outline the prospects for their further development. [Display omitted] • Ammonia synthesis cobalt catalysts deposited on lanthanide oxides were synthesised. • Lanthanide oxide supports act as electronic promoters of the metallic active phase. • In Co/Ln 2 O 3 systems Ln 2 O 3−x strong electron-donating sites are formed due to SMSI. • Promotion influence of Ln 2 O 3 depends on the ionic radius of the Ln3+ cation. • Growth of Ln3+ radius causes an exponential increase of catalyst TOF and basicity. [ABSTRACT FROM AUTHOR]

Interface and Morphology engineering strategies of electrocatalysts are of great importance to promote water splitting performance, although still facing many challenges. In this work, we present a facile method for preparing Ru-anchored hollow FeCoP nanocages electrocatalyst with ultrathin sheets. The hollow structure composed of ultrathin nanosheets and rich heterogeneous interfaces benefit the as-synthesized catalyst to exhibit small overpotentials of 310 mV and 94 mV at the current density of 10 mA·cm−2 for oxygen evolution reaction and hydrogen evolution reaction, respectively. When Ru-FeCoP nanocages were employed as the bifunctional catalyst for overall water splitting, the potential of 1.65 V was obtained to reach the current density of 10 mA·cm−2. The experimental results confirmed that the formation of hierarchical hollow structure facilitated the exposure of active sites and enhanced the electrocatalytic activity. Meanwhile, XPS and DFT data also reveal that the presence of heterogeneous interfaces changed the electronic structure, optimized the absorption of the intermediates, significantly reduced the energy barrier of water dissociation and promoted the release of H 2. This work offers an effective route for rational design of low-loading noble metal-anchored metal phosphide with the hierarchical hollow structure and rich interfaces towards overall water splitting. [Display omitted] • A novel Ru-anchored FeCoP hierarchical hollow nanocages with ultrathin nanosheets was designed and synthesized. • Ru-FeCoP nanocages demonstrated improved bifunctional catalytic activity and exceptional cycling stability for both oxygen evolution reaction and hydrogen evolution reaction in alkaline. • The strong interaction between Ru nanoparticles and FeCoP nanosheets optimizes the electronic structure and the adsorption of the intermediates. • The construction of the interface reduces the energy barrier of water dissociation and promotes electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ru deposited on TiO 2 (001) facets exhibited a superior activity for CO 2 methanation compared to TiO 2 with exposed (101) facets, because TiO 2 exposing (001) facets possesses high surface energy and abundant oxygen vacancies, which could provide more active sites for CO 2 activation and result in a strong metal-support interaction with Ru. Moreover, Ru deposited over TiO 2 (001) facets displayed an excellent durability for CO 2 methanation. • The type of TiO 2 facets dictates the catalytic performance in CO 2 methanation. • The superior activity of (001) facets originated from the enhanced CO 2 adsorption due to abundant surface oxygen vacancies. • The size-dependence behavior of Ru nanoparticles and the role of CO on the reaction pathway were elucidated. • Ru deposited onto TiO 2 nanocrystals displayed excellent durability for CO 2 methanation. Catalytic reduction of CO 2 to methane has been recognized as one of the most important strategic reactions to produce highly valuable chemicals and for storage of renewable energy (power-to-gas). This study demonstrates a crystal facet-dependent catalytic reduction of CO 2 to CH 4 on ruthenium nanoparticles deposited over TiO 2 nanocrystal with exposed (001) and (101) facets. Compared with TiO 2 (101) nanocrystal with the same Ru loading, Ru nanoparticles supported by TiO 2 (001) exhibited a highly enhanced CO 2 conversion rate and significantly improved methanation reactivity, along with a considerable durability. The physicochemical properties of the samples were characterized by HR-TEM, XRD, BET, FT-IR, UV–vis, Raman, ICP, and temperature-programmed reaction with CO 2 , and CO 2 + H 2. In view of the difference in catalytic activity and the physicochemical properties of the supported Ru/TiO 2 catalysts, the results uncovered that the nature of the catalyst support of Ru/TiO 2 strongly affected the dispersion of Ru species and the synergistic effect between Ru and underlying TiO 2 supporting materials due to the strong metal-support interaction, and thus affected their capability to activate CO 2 and determined the catalytic activity for CO 2 methanation. Our work demonstrated the important role of the exposed crystal facets of the underlying support and the resulting Ru particle which had a large effect on CO 2 methanation. [ABSTRACT FROM AUTHOR]

• Different particle size of Co nanoparticle from the controlled calcination of ZIF-67. • Selective hydrogenation of C O efficiently occurs on sub-1 nm Co and pyridinic-N. • Highly dispersed Ru—Co favors selective hydrogenation of C O under mild conditions. • Highly dispersed Ru—Co presents high hydrogenation stability of carbonyl compounds. Selective hydrogenation of biomass-derived oxygenated compounds to chemical and fuel is an important but challenging issue. In this paper, Co/NC catalysts with a Co species nanoparticle size from 0.4 to 6.6 nm are prepared by controlled calcination of ZIF-67. Ru-Co/NC is obtained by highly dispersed Co nanoparticle reducing Ru precursor. Co/NC-10 with 0.4 nm Co species nanoparticle shows higher catalytic performances for selective hydrogenation of ethyl levulinate than the other Co based catalysts and results from literatures due to the highly dispersed Co species. However, Co/NC-10 presents the low hydrogenation activity for biomass-derived carbonyl compounds under milder reaction conditions. In comparison with Co/NC-10, Ru-Co/NC enhances hydrogenation performance of various biomass-derived carbonyl compounds in the presence of high dispersed Ru-Co alloy. Electron transferring from Co to Ru renders Co electropositive and Ru electronegative, facilitating adsorption and hydrogenation of C O in carbonyl compounds on the interface of Ruδ−-Coδ+. Additionally, hydrogenation performances of ethyl levulinate and furfural remain stable on Ru-Co/NC after three cycles. This work provides an effective way for the selective hydrogenation of C O in biomass-derived compounds under mild conditions. [ABSTRACT FROM AUTHOR]

The manner of ammonia-containing wastewater in industrial production has always been an urgent issue that needs to be solved. Accordingly, a carbon-supported low-loading Ru/Cu bimetallic catalyst with high activity and hydrothermal stability was produced through facile disposal for catalytic wet air oxidation (CWAO). In the preparation process, Ru and Cu ions were loaded onto micro mesoporous carbon prepared through the calcination of potassium citrate by impregnation. Various characteristic techniques were utilized to characterize their structures and morphology, and results show that the calcination temperature with micro-mesopores' characteristics could regulate the morphology of carbon. The results of catalytic experiments demonstrated that the obtained catalyst showed excellent catalytic performance in the process of CWAO. The Ru/Cu@C-700 catalyst achieved 99.6 % conversion of ammonia water at 800 ppm and 99.1 % selectivity to nitrogen at 200 °C and 2 MPa O 2 in 4 h. The ammonia nitrogen content in the treated water was less than 15 ppm, meeting the standard for direct discharge. Moreover, no apparent deactivation phenomenon was observed after five cycles, indicating that the prepared catalyst can effectively prevent the leaching of ruthenium and copper nanoparticles. The low loading (less than 1 %) of the Ru/Cu bimetallic catalyst can significantly reduce costs and can synergistically enhance conversion and selectivity, providing an effective strategy for studying the CWAO of ammonia. [Display omitted] • The Ru-Cu bimetallic catalyst was prepared by a facile method for CWAO of ammonia. • Calcination temperature can regulate the morphology of carbon materials, thereby affecting catalytic performance. • The more defect sites on the carbon material, the higher its catalytic performance. • The synergistic catalysis of Ru-Cu can effectively improve catalytic activity and selectivity. • The Ru-Cu bimetal catalyst has a low loading (less than 1 %) and good stability. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The mechanisms of hydrogenation and hydrosilylation of nitrous oxide catalyzed by a ruthenium PNP pincer complex l have been studied through quantum chemistry calculations at the M06 level of theory. It was found that the catalytic cycle of hydrogenation of nitrous oxide contains three steps, hydrogenation of the dearomatized PNP pincer complex 1 , mono oxygen transfer and water release. In addition, the catalytic cycle of hydrosilylation of nitrous oxide also includes three steps, hydrosilylation of the dearomatized PNP pincer complex 1 , mono oxygen transfer, dehydrogenative coupling of silanol and silane/direct Si O bond coupling. The calculations suggested that the water molecule play an important role to lower the barrier for N 2 liberation. Frontier molecular orbital theory and NBO analysis indicated that nitrous oxide is activated by hydrido ligand via nucleophilical attacking. Present calculations are in good agreement with the experimental observations and can help to understand the activation of N 2 O. [ABSTRACT FROM AUTHOR]

A series of TiO 2 -supported Ru catalysts with different TiO 2 crystalline phases was synthesized and employed for the hydrogenolysis of polyethylene (PE). CO chemisorption, high-angle annular dark-field-scanning transmission electron microscopy, temperature-programmed reduction, and CO-Fourier transform infrared spectroscopy suggested that the degree of strong metal-support interactions (SMSIs) varied depending on the type of the TiO 2 phase and the reduction temperature, eventually influencing the catalysis of PE hydrogenolysis. Among the synthesized catalysts, Ru/TiO 2 with the rutile phase (Ru/TiO 2 -R) exhibited the highest catalytic activity after high-temperature reduction at 500 °C, indicating that a certain degree of SMSI is necessary for ensuring high activity in PE hydrogenolysis. Ru/TiO 2 -R could be successfully employed for the hydrogenolysis of post-consumer plastic wastes such as LDPE bottles to produce valuable chemicals (liquid fuel and wax) in high yields of 74.7%. This work demonstrates the possibility of harnessing the SMSIs in the design and synthesis of active catalysts for PE hydrogenolysis. [Display omitted] • A Ru/TiO 2 catalyst was developed for the efficient upcycling of plastic wastes. • Catalytic activity depended on the TiO 2 phase and metal-support interactions. • Upcycling was achieved through hydrogenolysis under mild conditions. • Valuable chemicals like liquid fuel and wax were produced upon hydrogenolysis. [ABSTRACT FROM AUTHOR]

A series of TiO 2 -supported Ru catalysts with different TiO 2 crystalline phases was synthesized and employed for the hydrogenolysis of polyethylene (PE). CO chemisorption, high-angle annular dark-field-scanning transmission electron microscopy, temperature-programmed reduction, and CO-Fourier transform infrared spectroscopy suggested that the degree of strong metal-support interactions (SMSIs) varied depending on the type of the TiO 2 phase and the reduction temperature, eventually influencing the catalysis of PE hydrogenolysis. Among the synthesized catalysts, Ru/TiO 2 with the rutile phase (Ru/TiO 2 -R) exhibited the highest catalytic activity after high-temperature reduction at 500 °C, indicating that a certain degree of SMSI is necessary for ensuring high activity in PE hydrogenolysis. Ru/TiO 2 -R could be successfully employed for the hydrogenolysis of post-consumer plastic wastes such as LDPE bottles to produce valuable chemicals (liquid fuel and wax) in high yields of 74.7%. This work demonstrates the possibility of harnessing the SMSIs in the design and synthesis of active catalysts for PE hydrogenolysis. [Display omitted] • A Ru/TiO 2 catalyst was developed for the efficient upcycling of plastic wastes. • Catalytic activity depended on the TiO 2 phase and metal-support interactions. • Upcycling was achieved through hydrogenolysis under mild conditions. • Valuable chemicals like liquid fuel and wax were produced upon hydrogenolysis. [ABSTRACT FROM AUTHOR]

• Fe 3 O 4 @HMCS/Ru has been synthesized and characterized successfully. • The peroxidase-like high activity can be attributed to the synergistic effects of magnetite and ruthenium nanoparticles, as well as the carbon support. • Comparative studies were conducted on Fe 3 O 4 @HMCS/Ru 's peroxidase-like activity. • It was found that the peroxidase activity was not significantly reduced after four cycles. Nanoenzymes with properties such as stability, high catalytic activity, easy recycling, and low cost have been subjected to considerable research to develop new enzyme-like heterogeneous catalysts. Carbon supports are very important in the construction of heterogeneous catalysts due to their biocompatibility and proper interaction with organic reactants. In this study, ruthenium nanoparticles were immobilized on magnetic hollow mesoporous carbon spheres. At first, hollow mesoporous carbon structures were synthesized by Stober's method. Through carbonization and subsequent etching with NaOH, the synthesized structures were transformed into hollow mesoporous spherical carbon structures. These hollow carbon spheres have been transformed into magnetic hollow carbon spheres after being impregnated with iron ions, freeze-drying, and then calcinated under inert conditions. Finally, these spheres were immobilized with ruthenium metal nanoparticles by wet chemical reduction. The peroxidase-like activity of the synthesized nanocomposites was evaluated in the oxidation of amine chromatic compounds of dopamine, ortho -phenylenediamine, and tetramethylbenzidine. Based on the results, these compounds have a lower Michaelis constant constant than hydrogen peroxide, which indicates a strong tendency to the enzymatic reaction. This high reactivity of the synthesized catalyst can be attributed to the synergistic effects of magnetite and ruthenium nanoparticles as well as the role of the carbon support. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrochemical reduction of nitrate (NO 3 -) wastewater to ammonia (NH 3) offers a promising but challenging approach for wastewater treatment of nitrate pollutants and resource recovery of ammonia fertilizer. However, the low catalytic activities and selective efficiency have limited their development and application. Herein, we report a facile chemical reduction method for the successful preparation of Ru nanoclusters (NCs) on ultrathin MoO 2 nanosheet substrates (Ru NCs/MoO 2 NSs). The Ru NCs/MoO 2 NSs electrocatalyst exhibits superior activity and selectivity for NO 3 - electroreduction to NH 3 , with an NH 3 yield rate of 50.9 mg·h−1·g−1 cat. at − 0.4 V and a faradaic efficiency of 83.5 % at − 0.3 V versus reversible hydrogen electrode. Operando electrochemical impedance spectroscopy further indicates the faster reaction kinetics of the Ru SCs/MoO 2 NSs at the electrode-electrolyte interfaces compared with MoO 2 NSs. In situ spectroscopic studies and on-line differential electrochemical mass spectrometry reveal the proposed reaction pathway for the conversion of NO 3 - to NH 3 , namely, deoxygenation reactions *NO 3 -→*NO 2 -→*NO and hydrogenation steps *NO→*NOH→*NH 2 OH→*NH 3. Density functional theory calculations further verify the effective N-end NOH pathway with the conversion of *NO to *NOH as the rate-determining step requiring a low energy barrier of 0.44 eV, which is lower than that of the O-end ONH pathway (1.17 eV). [Display omitted] • The Ru NCs/MoO 2 NSs catalyst is fabricated via a chemical reduction method. • Ru NCs/MoO 2 NSs catalyst exhibits a superior activity towards NH 3 synthesis. • Characterizations and theoretical calculation verify the reaction pathway. [ABSTRACT FROM AUTHOR]

Fabrication of cost-effective and an efficient catalyst is a greatly crucial to satisfy the requirements of removal of organic pollutants from the wastewater to ensure the green healthy environment yet remains vast challenge. In this regard, simple strategy has been adopted to develop the hybrid structure by employing the ruthenium (Ru) nanoparticles anchored on the metal-organic-framework (Ru@ZIF-8 and Ru@ZIF-67) interface and its overall photocatalytic performance was explored. Experimental results demonstrate that Ru@ZIF-8 hybrid exhibited a higher photocatalytic activity than that of the Ru@ZIF-67, ZIF-8 and ZIF-67 and the degradation efficiency of the crystal violet (CV; 96 %) and rhodamine B (RhB; 97.9) could attain under visible irradiations for about 80 min. In particular, the effects of CV dosage concentrations and various pH effects with the Ru@ZIF-8 hybrid were explored in detail. Moreover, the optimized Ru@ZIF-8 hybrid did not reveal the considerable loss of the photocatalytic activity after six cycles, revealing its long-term reusability and stability. The photocatalytic mechanism was conducted through trapping-species-experiment, confirming that superoxide (•O- 2) and electron (e-) contributed significant role in the degradation of the CV with Ru@ZIF-8 hybrid. Thus, the current study offers a new-strategy to design Ru@ZIF-8 as photocatalyst with higher photocatalytic performance for wastewater treatment. [Display omitted] • Ru@ZIF-8 hybrid are developed by solvothermal strategy and explored photocatalytic activity. • Ru@ZIF-8 hybrid exhibits a superior photocatalytic activity for the RhB and CV reduction. • The Ru@ZIF-8 hybrid shows the high performance of the CV at the pH = 7 and CV dosage = 5 mg/mL. • Extreme accessibility, excellent stability was found by using six cycles with Ru@ZIF-8 hybrid. • Significantly, ●O- 2 was found main ROS towards the degradation of the CV with Ru@ZIF-8 hybrid. [ABSTRACT FROM AUTHOR]

Ru(III) modified melamine formaldehyde polymers were synthesized by simple hydrothermal method. Extensive characterization of the materials by FT-IR, XRD, XPS, SEM, TEM, EDX, 13C solid NMR, TGA, CO 2 -TPD, CO 2 -physiorptaion and N 2 -physisorption showed that they exhibited a macro/mesoporous were structure with Ru(III) sites coordinated to the electron rich/weakly basic N-species. These low-cost polymeric materials presented excellent activity as heterogeneous catalysts for selective hydrogenation of CO 2 derived carbonate/bicarbonates present in CO 2 -rich scrubbing solvents (amine and as well as inorganic base derived) to formate/formic acid. The low-cost polymeric catalysts outperformed various benchmark catalysts (Ru/LDH , Ru/MgO, Ru/AC, Ru/NAC, Ru/gC 3 N 4 , Pd/AC Sigma etc.) affording near stoichiometric formate yields (0.51–1.84 M) under relatively mild conditions (120 °C, 3 MPa, 5–10 h). The polymeric catalysts were robust and demonstrated excellent reusability in batch mode, as well as stable performance for continuous formate/formic acid production in a lab scale fixed-bed reactor (verified during ca. 270 h time on stream, 80 °C, 5.5 MPa, WHSV feed : 7.2 h−1, feed: CO 2 saturated aq. triethylamine). The excellent activity, selectivity and stability of the polymeric catalyst was attributed to the presence of stable Ru(III) sites coordinated to the robust and hydrothermally stable melamine formaldehyde framework. Most importantly, this work represents the first example of continuous integrated CO 2 capture and conversion to formic acid using a solid catalyst. [Display omitted] • Ru(III) modified porous melamine for CO 2 hydrogenation to formic acid. • Continuous integrated CO 2 capture and conversion to formic acid. • Near stoichiometric formate yields (0.51–1.84 M). • Stable performance during ca. 270 h time on stream (negligible Ru leaching). [ABSTRACT FROM AUTHOR]

Hafnium oxide (HfO 2) nanohybrids with metal nanoparticle incorporation were fabricated to develop a prominent photocatalyst for environmental water treatment. The synthesis of ruthenium/platinum nanoparticles-incorporated HfO 2 (Ru/HfO 2 and Pt/HfO 2) was done using a simple hydrothermal technique. The as-synthesized nanohybrids were well characterized; HfO 2 had a Nanoleaf morphology, whereas Ru/HfO 2 and Pt/HfO 2 both had evenly attached Ru and Pt NPs on the surface of HfO 2 , respectively. These nanohybrids were utilized as a photocatalyst for the degradation of antibiotics nitrofurantoin (NFT) and ciprofloxacin (CIP) in an aqueous solution by leveraging the inherent benefits of metal oxides and metal nanoparticles. Both nanohybrids displayed splendid photocatalytic activity, for instance, Ru/HfO 2 exhibited ∼100% degradation of NFT and CIP in 15 and 25 min with rate constants of 0.3280 and 0.1919 min−1, respectively. The photocatalytic degradation mechanism was validated by using reactive species scavenging studies and mass spectrum analysis; the achieved degradation was predominantly governed by the hydroxyl radicals through an oxidation pathway. Moreover, metal nanoparticles play a vital role in trapping photo-excited electrons, which improves catalytic activity. The sustainable nature of nanohybrids was validated by investigating their reusability and practical applicability in real samples analysis. This HfO 2 -based nanohybrid is anticipated to generate a wide platform for developing imminent materials for use in a variety of environmental remediation applications. [Display omitted] • Ru/HfO 2 and Pt/HfO 2 were fabricated for the photocatalytic degradation of antibiotics. • HfO 2 featured a Nanoleaf-shaped morphology. • Both nanohybrids showed superior photocatalytic activity towards nitrofurantoin and ciprofloxacin. • Nearly 100% degradation efficiency was achieved within a short period. [ABSTRACT FROM AUTHOR]

Density functional theory calculations at the M06-2X/6-31G(d,p) (RECPs for Ru) level of theory are performed to explore the reaction mechanism for the cycloisomerization of silicon-tethered 1,7-enynes using CpRuCl as a catalyst. The solvent effect is taken into account by M06-2X/6-311++G (d,p) single-point calculations with SMD solvation model in toluene. The calculation results indicate that the reactions of the ruthenium-catalyzed cycloisomerization of 1,7-enynes occur through the possible mechanisms and get five-membered ring or six-membered ring products, respectively. The process of forming six-membered ring product is more favored kinetically with the barrier of 13.6 kcal/mol for Ph group, while the energy barrier for five-membered ring product becomes relatively higher of 34.3 kcal/mol. The above reaction mechanism indicates that the ruthenium-catalyzed cycloisomerization of silicon connected 1,7-enynes has high regioselectivity, which is consistent with the experimental observations of Kaminsky and Clark. [ABSTRACT FROM AUTHOR]

The substituent effect of the pentafluorophenyl (PhF 5 ) groups on the Ru-porphyrin complex-catalyzed intramolecular reaction was investigated with density function theory calculations. The interested reaction steps are the unsubstituted and substituted Ru-porphyrin complexes-mediated nitrene insertion into one of the C H bonds on a certain sulfamate ester. For both of the unsubstituted and substituted reactant complexes, the singlet state has a close energy to the triplet state. The substitution of the PhF 5 groups leads to a lowered reaction barrier on both of the singlet and triplet potential energy surfaces (PESs). The barrier lowering corresponds to an increased reaction rate by 2 orders of magnitude on both PESs. The singlet PES has a predominant contribution to the overall reaction rate compared to the triplet one for both of the unsubstituted and substituted cases. The results from the natural bond orbital analysis show that the PhF 5 groups are highly negative in charge, and the group substituting leads to an increased electron deficiency of the nitrene N atom. This increase can account for the increase of the reaction rate on both of the singlet and triplet PESs. [ABSTRACT FROM AUTHOR]

• Ultrafine Ru NPs supported by Co 3 O 4 /NC were successfully developed. • Ru@Co 3 O 4 /NC was utilized as a potential to increase the efficiency for the hydrolysis of AB. • The catalytic process was enhanced by large number of accessible active sites, efficient electron transport, and electronic synergy. • Ru@Co 3 O 4 /NC has a catalytic activity of 883 min−1, a low activation energy of 32.07 kJ mol−1, and is recyclable and could be reused at least 10 times without loss. Evolving cost-effective and high-efficiency catalysts for efficient ammonia borane (AB) hydrolysis is highly desired but leftovers are a great challenge. Catalysis with high efficiency may be achieved by rationally modifying the intention and electronic state. The development of carbonized zeolite imidazole framework (ZIF-67) based Ru nanoparticles (NPs) dispersed Ru@Co 3 O 4 /NC-350 NPs catalyst composition was prepared for the carrier catalysts. The ZIF-67 was introduced with different calcination temperatures for the carbonized porous materials. Only the calcination temperature at 350 °C with Ru@Co 3 O 4 /NC-350 NPs shows the good ability in its catalytic activity. The addition of 3.0 wt.% Ru NPs into the hollow ZIF-67 porous metal-organic framework (MOF) yielded highly stable with good morphology and porous. Ru NPs dispersed on carbonized Co 3 O 4 /NC have a hollow porous structure with a convoluted nano restricted inner region between Co 3 O 4 and NC, allowing for a large number of accessible active sites and easy mass transfer and controlling the carbonized temperature can change the composition of Co 3 O 4 /NC heterostructures. These hollow porous carbon materials show much higher turnover frequency during a very short time and also high stability after ten cycles for the AB hydrolysis. This carbonized sample of Ru@Co 3 O 4 /NC-350 NPs exhibited increased catalyst stability and materials reusability. There is particularly great potential for industrial application of this catalytic system in fuel cells, because of its simple preparation method, the use of relatively cheap metals, and its highly active catalysis. [Display omitted] [ABSTRACT FROM AUTHOR]

Selective catalytic reduction of nitric oxide using ammonia in the presence of excess oxygen remains a major challenge. In the present work, we developed mesoporous Al-SBA-15 supported NiRu catalysts with a high surface area and ordered mesoporous structure. The monometallic Ni catalyst were prepared by the modified beta-cyclodextrin impregnation method by maintaining 1/50 mol of β-CD/Ni and bimetallic NiRu catalyst was prepared by maintaining constant loading of 8 wt% Ni with different wt%. loading of xwt% Ru (x = 2, 4, 6 and 8). The developed catalysts were characterized by XRD, N 2 sorption, FT-IR, Py-IR, UV-DRS, HRSEM, HRTEM and XPS. The NH 3 -SCR efficiency of both monometallic (Ni) and bimetallic (NiRu) catalysts are discussed. Additionally, monometallic 8 wt% Ni and Ru supported catalysts have been also synthesized by the conventional impregnation method for purposes of comparison. The remarkable low-temperature NH 3 -SCR conversion (90.2% NO conversion at 300 °C) of 8Ru8Ni/Al-SBA-15 catalyst under excess oxygen condition (7%) and superior % promotion (87%) of ruthenium addition was demonstrated with excellent textural properties, stability and corroborated with the physicochemical properties of the catalyst. [Display omitted] • NiO and RuO 2 prepared by modified β-CD impregnation method. • High surface area Al-SBA-15 is used as support for NiRu catalyst. • NH 3 SCR on NiRu/Al-SBA-15 was investigated between 100 and 400 °C under 7% O 2 in fixed bed reactor. • Enhanced promotional effect of Ru is responsible for enhanced activity at low temperature. [ABSTRACT FROM AUTHOR]

The paper examined the catalysts of low-temperature ammonia synthesis Ru-Cs/Sibunit in which Sibunit, mesoporous carbon carrying agents, vary considerably in specific surface area and pore volume, but the pore sizes are similar. According to Raman spectroscopy, the Sibunit structures are same. Applied ruthenium dispersiveness, determined by CO chemisorption, are also close (∼ 13 - 16%) for all the examined catalysts. The difference in the activity of the samples is due to the different direct contact probability of the particles of ruthenium and modifier (CsO x ). This probability decreases with increasing specific surface area ( S BEТ Sibunit) that are supposed to cause the decrease of catalyst activity on high-superficial Sibunit in the ammonia synthesis reaction. [ABSTRACT FROM AUTHOR]

Nanocrystalline Mg-doped ruthenium dioxide catalysts with the formula Rui-xMgxO2 (0 ≤ x ≤ 20) were synthesized by the sprayfreezing freeze-drying technique. Synthesized materials are of nanoparticulate nature and show a single phase diffraction pattern conforming to a tetragonal oxide of the rutile structural type. Magnesium ions are not distributed homogeneously in the material, but exist in Mg-rich clusters as shown by X-ray absorption spectroscopy. The refinement of the Mg EXAFS functions for materials with low Mg content shows that the magnesium rich clusters contain Mg in a highly strained environment similar to that of the rutile-type structure. The Mg environment shifts to an ilmenite-type inclusion when Mg occupies more than 10% of all cationic positions. All Mg modified materials are active in oxygen evolution and chlorine evolution reactions. Although the Mg containing catalysts show lower overall activities compared with the non-doped ruthenia, they feature enhanced selectivity toward the chlorine evolution process, which is attributed primarily to the opening of a reaction pathway for chlorine evolution associated with presence of Mg modified active sites. [ABSTRACT FROM AUTHOR]

Mongolian oak (MO), a lignocellulosic biomass feedstock comprising lignin, hemicellulose, and cellulose, was fractionated via reductive catalytic fractionation (RCF) into holocellulose-rich solid residue and lignin-derived phenol-rich liquid oil. To achieve an economically feasible RCF process, tungstate-zirconia (WZr)-supported metal catalysts, exhibiting bifunctionalities of hydrogen-adsorbing metal and acidic WZr, were used for depolymerizing and valorizing lignocellulose, and their catalytic activity was found to be highly dependent on the deposited metal. Ru/WZr exhibited excellent fractioning ability, achieving a maximum yield of 23.6 wt% of monomeric and dimeric compounds from MO and exhibiting the potential to be techno-economically viable. The superior activity of Ru/WZr can be attributed to the synergistic effects of metal and acid, which were studied by investigating the product distributions of aromatic small molecules depending on the properties of WZr-supported metal catalysts. The stabilization of reactive radical intermediates depending on the surface Brønsted acidity of acid catalysts and hydrogen-adsorbing ability of metals were also investigated. RCF reaction conditions were optimized for the maximum yield of monomeric compounds, which can be beneficial for the further development of industrial processes. [Display omitted] • Hardwood was fractioned using tungstate-zirconia-supported metal catalysts. • Phenols, carbohydrate-derived compounds, and pulp-rich solids were obtained. • Combined acidity and reductivity improved the catalytic fractionation. • Catalysis produced 33.5 wt% phenolic compounds from Mongolian oak. • Catalysis produced 61.9 wt% phenolic monomers from lignin fraction. [ABSTRACT FROM AUTHOR]

While H 2 gas is conventionally purged during hydrogenation of bromate in the presence of catalysts, the low solubility of H 2 gas leads to wasteful consumption of H 2 gas. Reductants in solid forms, which act as storage media of H 2 , would be preferable, and borohydrides, including NaBH 4 , and NH 3 BH 3 are promising candidates. Although ruthenium (Ru) is an efficient catalyst for releasing H 2 from these borohydrides, almost no studies have looked into usage of Ru with borohydrides for reducing bromate, and differences between NaBH 4 , and NH 3 BH 3 for reducing bromate in the presence of Ru. Therefore, the goal of this study aims to compare hydrogenation of bromate using different borohydrides as well as H 2 gas purge under different conditions in the presence of Ru/C as the most representative Ru catalyst. While Ru/C could slowly reduce bromate to bromide, the addition of NaBH 4 or NH 3 BH 3 would tremendously accelerate bromate removal and bromide production. Nevertheless, the H 2 purge might cause interferences with the entire reaction, thereby leading to ineffective bromate reduction. Moreover, Ru/C+NaBH 4 would lead to an even faster bromate reduction because adsorption of BH 4 – to Ru/C was much more favorable according to the DFT calculation. The E a of bromate reduction by Ru/C+NaBH 4 is also lower than that by Ru/C+NH 3 BH 3 , validating the promising advantage of NaBH 4 over NH 3 BH 3. Ru/C+NaBH 4 could be also reusable for reducing bromate to bromide, demonstrating that borohydrides might be promising alternatives to H 2 purge for reducing bromate to bromide in order to achieve even faster and more efficient bromate reduction. [Display omitted] • Borohydrides are comprehensively compared with direct H 2 purge for bromate reduction. • Most typical borohydrides, NaBH 4 and NH 3 BH 3 , are compared for bromate reduction. • NaBH 4 and NH 3 BH 3 can enable much faster bromate reduction by Ru/C than H 2 purge. • DFT calculation validates NaBH 4 as a more favorable borohydride for bromate reduction. • Ru/C+NaBH 4 exhibits a lower E a than that of Ru/C+NH 3 BH 3 for bromate reduction. [ABSTRACT FROM AUTHOR]

The investigation of Ru/Mn/Ce/Al2O3 catalyst on the ceria loading, calcination temperature and catalyst dosage had significantly affected the catalytic performance. The optimum conditions were achieved over 10 g of Ru/Mn/Ce/Al2O3 catalysts calcined at 1000 °C with 65 wt% of Ce loading which gave 97.73% CO2 conversion and 91.31% of methane formation at reaction temperature of 200 °C. The physicochemical properties investigated by XRD diffractogram showed that the catalyst still having polycrystalline structure with the mixture of Mn4+ and Mn3+ although had being calcined at high temperature of 1000 °C. Meanwhile, FESEM analysis indicated a morphology which looks like staghorn coral morphology with the smallest particle size of 86 nm and the highest BET surface area of 47.65 m2/g. The impact of these three critical parameters was investigated via Box–Behnken experimental design and their optimum values obtained over 10 g of Ru/Mn/Ce/Al2O3 catalyst were calcined at 1025 °C with Ce loading of 65 wt%. The predicted value given was 98.95% of CO2 conversion which was closely agreed with our experimental result (98.25%) over similar conditions. [ABSTRACT FROM AUTHOR]

Highlights: [•] The proposed mechanism detects free radicals. [•] In the mechanism obtained products were identified and characterized by TLC and FT-IR. [•] A design kinetic rate laws. [•] Find out the reactive species and activation parameters. [•] Catalytic efficiency of Ru(III) and the rate constant was evaluated at the slow step. [ABSTRACT FROM AUTHOR]

The increase in greenhouse gas emissions due to high consumption of fossil fuels is one of the key contributors to climate change. Conversion of biomass into valuable chemicals via hydrogenolysis reaction is regarded as an alternative approach to address this matter, particularly through catalytic hydrogenolysis of sorbitol. Unfortunately, the deactivation of the catalyst has limited its industrial application. Therefore, new compelling catalysts that may enhance the performance of hydrogenolysis reaction has garnered considerable interest. Ruthenium-based catalyst has a high potential as it demonstrated high catalytic activity in most studies. The effect of metal (monometallic and bimetallic), supporting material and acid/base properties have significant effects on catalytic performance. This review is an attempt to provide a recent summary on the sorbitol hydrogenolysis over heterogeneous catalysts, involving the aspects of the catalysts, reaction mechanism and deactivation, as well as future opportunities on the studies. [Display omitted] • Crucial step in sorbitol hydrogenolysis: C-C and C-O bonds cleavage via retro-aldol condensation. • Predominant catalyst in sorbitol hydrogenolysis: Ni and Ru-based catalysts. • Challenges: (i) Promoting main reaction while inhibiting the undesired side reactions; (ii) Maintaining catalyst stability. • Strategies maintaining catalyst stability: (i) Using optimum process conditions; (ii) Apply regeneration process. [ABSTRACT FROM AUTHOR]

• Plasma-catalytic CO 2 hydrogenation to ethane was achieved in a DBD reactor. • The effect of different metal catalysts on this reaction was evaluated. • The Ru/Al 2 O 3 catalyst attained the highest C 2 H 6 selectivity of ∼40%. • This process offers a new route for CO 2 conversion under mild conditions. Anthropogenic greenhouse gas emissions have caused changes to the Earth's climate, resulting in catastrophic weather events that are becoming more frequent and intense. Developing carbon-neutral processes for CO 2 conversion powered by renewable energy is one way of attaining a circular economy, as waste CO 2 is converted to a new carbon-containing product, without also being created as a by-product during the process. Plasma-catalysis is gaining increasing interest for CO 2 conversion and utilisation under mild conditions, particularly CO 2 conversion to green chemicals and fuels using renewable hydrogen, as this electrified process can easily be combined with clean and renewable energy to ensure a carbon-neutral process. Previous studies have mainly focussed on the production of methane from CO 2 and H 2 ; however, ethane (C 2 H 6) is a much more valuable product. In this work, we report a non-thermal plasma-catalytic process for the conversion of CO 2 into C 2 H 6 in a dielectric barrier discharge (DBD) reactor. The influence of a variety of alumina-supported metal catalysts (Ru, Cu, Ni and Fe) on the plasma-catalytic CO 2 hydrogenation to C 2 H 6 was evaluated. The Ru catalyst attained the highest selectivity towards C 2 H 6 , at almost 40%. The Ru catalyst also increased the energy efficiency of the process to around 18%, in comparison to the plasma reaction using pure alumina (12%). The Ru catalyst also achieved the highest H 2 conversion at 29%. Plasma-assisted production of C 2 H 6 is a new promising process for the utilisation of CO 2 via carbon-neutral electrified gas conversion. [ABSTRACT FROM AUTHOR]

Highlights: [•] Superhydrophobic, chiral, and mesoporous TsDPEN copolymer catalyst was synthesized. [•] The catalyst exhibits high activities and excellent recyclabilities in ATH reactions. [•] The catalyst shows better catalytic performance than the homogeneous catalyst. [•] The enhanced catalyst performance relates to reactant enrichment and product transfer. [•] The superhydrophobicity is responsible for reactant enrichment and product transfer. [ABSTRACT FROM AUTHOR]

Abstract: Density functional theory (DFT) calculations were used to predict and rationalize the effect of the modification of the structure of the prototype 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) (IPr) N-heterocyclic carbene (NHC) ligand. The modification consists in the substitution of the methyl groups of ortho isopropyl substituent with phenyl groups, and here we plan to describe how such significant changes effect the metal environment and therefore the related catalytic behaviour by simple steric maps. Bearing in mind that there is a significant structural difference between IPr and IPr* ligands, that translated in different reactivity for several olefin metathesis reactions, here by means of DFT we characterize where the NHC ligand plays a more active role and where it is a simple spectator, or at least its modification does not significantly change its catalytic role/performance. Furthermore, this communication endeavours to modify further the skeleton of the IPr NHC ligand. The optimization of these bulky new systems go to the limits of the DFT computational method. [Copyright &y& Elsevier]

Abstract: Volatile Organic Compounds (VOCs) from industrial coating operations could be valuable energy resources if collected and used effectively. A promising approach is to generate syngas stream for Solid Oxide Fuel Cells (SOFCs) application by autothermal reforming of them. However, conventional nickel-based catalysts with whatever promoters/supports or formulations are not very successful for this process for lacking of activities or deactivating quickly due to sintering or carbon deposition at the presence of high percentage of aromatic compounds or sulfur chemicals. By contrast, there also exist many big challenges for precious metal-based catalysts in terms of longevity and cost effectiveness. In this paper, Ruthenium noble metal dispersed in a formulation of pyrochlore structure was explored, and various VOCs with wide range of monoaromatics additives of various species and fairly amount of naphthalene was used as fuels to simulate actual VOCs. It was found that this catalyst not only had quite good initial activity but also showed very good stability during the longevity tests, which was considered as important as, if not more important than, the former for commercialization. Eventually, actual VOC collected from a painting-booth was tested for this autothermal reforming process. The longevity test verified the high activities and good stabilities of this catalyst. Most likely the precious metal atomically dispersed in a stable structure of pyrochlore contributed to the super performance, although fundamental studies to understand the reaction mechanism was much needed. [Copyright &y& Elsevier]

Abstract: Different catalysts based on ruthenium impregnated on hydrotalcites (Ru/CoxMgyAl2-HT) were prepared by wet impregnation from aqueous nitrosyl nitrate solutions and activated under air at 600°C for 4h. The reactivity of the catalysts was evaluated in the oxidation of carbon black (CB). The results showed that the best catalyst decreased the temperature at which the rate of carbon black oxidation is the highest by about 150°C. This good reactivity was attributed to the formation of easily reducible ruthenium and cobalt oxide species at the surface of the support. The addition of ruthenium made the reduction of surface and bulk cobalt oxides possible at lower temperatures. [Copyright &y& Elsevier]