Surface engineering on a nanocatalyst: basic zinc salt nanoclusters improve catalytic performances of Ru nanoparticles

2016 ◽  
Vol 4 (45) ◽  
pp. 17694-17703 ◽  
Author(s):  
Zhikun Peng ◽  
Xu Liu ◽  
Huinan Lin ◽  
Zhuo Wang ◽  
Zhongjun Li ◽  
...  
Keyword(s):  
Active Sites ◽  
Surface Engineering ◽  
Hydrogenation Reaction ◽  
Zinc Salt ◽  
Sulfate Salt ◽  
Ru Catalyst ◽  
Ru Nanoparticles ◽  
Surface Modified ◽  
Line P ◽  
Catalytic Performances

Ru active sites armed with surface BZSS (basic zinc sulfate salt) nanoclusters induced high selectivity and yield for the benzene-selective hydrogenation reaction. The surface-modified Ru catalyst operated stably for more than 600 h on an industrial production line.

Ru nanoparticle functionalized silica nanotubes as a catalyst for CO2 hydrogenation reaction

2021 ◽  
Vol 18 ◽  
Author(s):  
Vivek Srivastava
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Chemical Properties ◽  
Hydrogenation Reaction ◽  
Active Species ◽  
Co2 Hydrogenation ◽  
Functionalized Silica ◽  
Tem Analysis ◽  
Silica Nanotubes ◽  
Ru Catalyst

: The catalytic display of supported heterogeneous catalysts is essentially reliant on their constitutive elements including active species and supports. Accordingly, the scheme and development of active catalysts with synergistically enhanced outcomes between active sites and supports are of high importance. A simple NaBH4 reduction method was used to synthesize cylindrical amine-functionalized silica nanotubes supported Ru catalyst (ASNT@Ru catalyst) including amine functionality. The physicochemical properties of the material were analyzed by various analytical methods such as SEM-TEM analysis, N2 physisorption, ICP-OES, XPS, etc, and all the data were found in good agreement with each other. Amine-free SNT support using the calcination process was also synthesized to examine the effect of amine in ASNT support on the uniform Ru dispersion. Taking the advantages of the fundamental physical and chemical properties of ASNT support and well-distributed Ru NPs, the ASNT@Ru catalyst was utilized for CO2 hydrogenation reaction and gave excellent catalytic activity/ stability in terms of a good quantity of the formic. 5 times catalysts recycling were recorded, and formic acid was obtained in good quantity.

scholarly journals ZnO/RGO Heterojunction Based near Room Temperature Alcohol SENSOR with Improved Efficiency

2021 ◽  
Vol 6 (1) ◽  
pp. 25
Author(s):  
Sanghamitra Ghosal ◽  
Partha Bhattacharyya
Keyword(s):  
Active Sites ◽  
Room Temperature ◽  
Surface Engineering ◽  
Gas Sensing ◽  
Energy Band Diagram ◽  
Future Generation ◽  
High Yield ◽  
Synthesis Process ◽  
Ethanol Sensor ◽  
Vapor Sensing

The systematic optimization of surface engineering (dimensionality) indeed plays a crucial role in achieving efficient vapor-sensing performance. Among various semiconducting metal oxides, owing to some of its unique features and advantages, ZnO has attracted researchers on a global scale due to its application in various fields, including chemical sensors. The concomitant optimization of the surface attributes (varying different dimensions) of ZnO have become a sensation for the entire research community. Moreover, the small thickness and extremely large surface of exfoliated 2D nanosheets render the gas sensing material an ideal candidate for achieving strong coupling with different gas molecules. However, temperature is a crucial factor in the field of chemical sensing. Recently, graphene-based gas sensors have attracted attention due to their variety of structures, unique sensing performances and room temperature working conditions. In this work, a highly sensitive and fast responsive low temperature (60 °C)-based ethanol sensor, based on RGO/2D ZnO nanosheets hybrid structure, is reported. After detailed characterizations, the vapor sensing potentiality of this sensor was tested for the detection of ethanol. The ethanol sensor offered the response magnitude of 89% (100 ppm concentration) with response and recovery time of 12 s/29 s, respectively. Due to excessively high number of active sites for VOC interaction, with high yield synthesis process and appreciably high carrier mobility, this has paved the way for developing future generation, miniaturized and flexible (wearable) vapor sensor devices, meeting the multidimensional requirements for traditional and upcoming (health/medical sector) applications. The underlying mechanistic framework for vapor sensing, using this hybrid junction, is explained with the Energy Band Diagram.

Promotive Selectivity to C2-C3 Polyols From Alkaline Cellulose Hydrogenated by Ionic Liquid-stablized Ru Nanoparticles

2021 ◽  
Author(s):  
Mingrui Liu ◽  
Hua Wang
Keyword(s):  
Ionic Liquid ◽  
Ethylene Glycol ◽  
Conversion Rate ◽  
Metal Salt ◽  
Hydrogenation Reaction ◽  
Metal Catalyst ◽  
Ru Nanoparticles ◽  
Naoh Solution ◽  
Plausible Mechanism ◽  
Amorphous Part

Abstract Alkaline cellulose hydrogenolysis on metal catalyst was an effective way to get C2~C3 polyols. The alkaline cellulose was obtained by treating cellulose with 4 wt% NaOH solution. Ionic liquid-stablized Ru nanoparticles were prepared by reducing metal salt in ionic liquid. The SEM results indicate that the amorphous part of alkaline cellulose is helpful for getting the catalyst into the cavities to have a further hydrogenation reaction. When hydrogenolysis of alkaline cellulose over Ru/[Bmim]BF4 nanoparticles was conducted at 433 K, 63.78% of the substrate was converted with glycerol, 1,2-propanediol and ethylene glycol as main products of which selectivity was up to 58.91 %, whereas the conversion rate over Ru/C catalyst of alkaline cellulose was 59.23 % and only 26.11 % C2~C3 polyols were detected. Moreover, if the ionic liquid-stablized Ru nanoparticles were doped with 53.7 % Ni, the selectivity of C2~C3 polyols was promoted to 65.07 %. These results suggested the advantages of the ionic liquid-stablized Ru nanoparticles, especially doping with Ni, have potentials for promotive selectivity to C2~C3 alcohols. Put forward the plausible mechanism finally.

scholarly journals Ru Catalyst Encapsulated into the Pores of MIL-101 MOF: Direct Visualization by TEM

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4531
Author(s):  
Maria Meledina ◽  
Geert Watson ◽  
Alexander Meledin ◽  
Pascal Van Der Voort ◽  
Joachim Mayer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Dark Field ◽  
Catalyst Nanoparticles ◽  
Ru Catalyst ◽  
Ru Nanoparticles ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Annular Dark Field

Ru catalyst nanoparticles were encapsulated into the pores of a Cr-based metal-organic framework (MOF)—MIL-101. The obtained material, as well as the non-loaded MIL-101, were investigated down to the atomic scale by annular dark-field scanning transmission electron microscopy using low dose conditions and fast image acquisition. The results directly show that the used wet chemistry loading approach is well-fitted for the accurate embedding of the individual catalyst nanoparticles into the cages of the MIL-101. The MIL-101 host material remains crystalline after the loading procedure, and the encapsulated Ru nanoparticles have a metallic nature. Annular dark field scanning transmission electron microscopy, combined with EDX mapping, is a perfect tool to directly characterize both the embedded nanoparticles and the loaded nanoscale MOFs. The resulting nanostructure of the material is promising because the Ru nanoparticles hosted in the MIL-101 pores are prevented from agglomeration—the stability and lifetime of the catalyst could be improved.

Geometric and Electronic Effects Contributing to N2 Dissociation Barriers on a Range of Active Sites on Ru Nanoparticles

2019 ◽  
Vol 123 (50) ◽  
pp. 30458-30466 ◽  
Author(s):  
Caitlin A. Casey-Stevens ◽  
Stephanie G. Lambie ◽  
Charlie Ruffman ◽  
Egill Skúlason ◽  
Anna L. Garden
Keyword(s):  
Active Sites ◽  
Electronic Effects ◽  
Ru Nanoparticles

scholarly journals Evaluation of a Catalyst Durability in Absence and Presence of Toluene Impurity: Case of the Material Co2Ni2Mg2Al2 Mixed Oxide Prepared by Hydrotalcite Route in Methane Dry Reforming to Produce Energy

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1362
Author(s):  
Carole Tanios ◽  
Cédric Gennequin ◽  
Madona Labaki ◽  
Haingomalala Lucette Tidahy ◽  
Antoine Aboukaïs ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxide ◽  
Active Sites ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Side Reactions ◽  
Commercial Catalyst ◽  
Catalytic Sites ◽  
Catalyst Durability ◽  
Catalytic Performances

Ni, Co, Mg, and Al mixed-oxide solids, synthesized via the hydrotalcite route, were investigated in previous works toward the dry reforming of methane for hydrogen production. The oxide Co2Ni2Mg2Al2 calcined at 800 °C, Co2Ni2Mg2Al2800, showed the highest catalytic activity in the studied series, which was ascribable to an interaction between Ni and Co, which is optimal for this Co/Ni ratio. In the present study, Co2Ni2Mg2Al2800 was compared to a commercial catalyst widely used in the industry, Ni(50%)/Al2O3, and showed better activity despite its lower number of active sites, as well as lower amounts of carbon on its surface, i.e. less deactivation. In addition to this, Co2Ni2Mg2Al2800 showed stability for 20 h under stream during the dry reforming of methane. This good durability is attributed to a periodic cycle of carbon deposition and removal as well as to the strong interaction between Ni and Co, preventing the deactivation of the catalyst. The evaluation of the catalytic performances in the presence of toluene, which is an impurity that exists in biogas, is also a part of this work. In the presence of toluene, the catalytic activity of Co2Ni2Mg2Al2800 decreases, and higher carbon formation on the catalyst surface is detected. Toluene adsorption on catalytic sites, side reactions performed by toluene, and the competition between toluene and methane in the reaction with carbon dioxide are the main reasons for such results.

Catalytic Oxidation of Formaldehyde Over Mesoporous MnOx-CeO2 Catalysts

2015 ◽  
Vol 14 (01n02) ◽  
pp. 1460028 ◽  
Author(s):  
Yanlei Zhao ◽  
Hua Tian ◽  
Junhui He ◽  
Qiaowen Yang
Keyword(s):  
Low Temperature ◽  
Indoor Air ◽  
Active Sites ◽  
Harmful Effect ◽  
Practical Interest ◽  
Catalytic Performance ◽  
Air Pollutant ◽  
Ordered Mesoporous ◽  
Formaldehyde Oxidation ◽  
Catalytic Performances

Formaldehyde is regarded as the major indoor air pollutant. Because of harmful effect on human health, its emission abatement is of significant practical interest. We report here excellent low-temperature catalytic performances of mesoporous MnO x - CeO 2 catalysts in the process of formaldehyde oxidation. These MnO x - CeO 2 catalysts were synthesized by a "nanocasting" method using SBA-15 as hard template. TEM images showed that the as-fabricated MnO x - CeO 2 composites possess well-ordered mesoporous architectures. Results of catalytic tests revealed that mesoporous MnO x - CeO 2 nanocomposites have excellent low-temperature catalytic activity for formaldehyde oxidation, the temperature for 100% formaldehyde conversion can be as low as 65°C over these noble-metal-free mesoporous catalysts. The excellent catalytic performance is attributed to their ordered mesoporous structures that expose abundant active sites to formaldehyde molecules.

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