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.

Hydrotalcite Anchored Ruthenium Catalyst for CO2 Hydrogenation Reaction

2019 ◽  
Vol 16 (5) ◽  
pp. 396-408
Author(s):  
Vivek Srivastava
Keyword(s):  
Ionic Liquid ◽  
Formic Acid ◽  
Catalytic System ◽  
Acid Synthesis ◽  
Hydrogenation Reaction ◽  
Significant Loss ◽  
Co2 Hydrogenation ◽  
Catalyst Stability ◽  
Catalyst Recycling ◽  
Tem Analysis

We developed a series of new hydrotalcite functionalized Ru catalytic system to synthesize formic acid via CO2 hydrogenation reaction. Advance analytical procedures like FTIR, N2 physisorption, ICP-OES, XPS, and TEM analysis were applied to understand the physiochemical nature of functionalized hydrotalcite materials. This well-analyzed system was used as catalysts for CO2 hydrogenation reaction (with and without ionic liquid medium). Ru metal containing functionalized hydrotalcite materials were found highly active catalysts for formic acid synthesis via hydrogenation reaction. The concern of catalyst stability was studied via catalysts leaching and recycling experiments. We recycled the ionic liquid mediated functionalized hydrotalcite catalytic system up to 8 runs without any significant loss of catalytic activity. Surprisingly, no sign of catalyst leaching was recorded during the catalyst recycling experiment.

Hydrotalcite Anchored Ruthenium Catalyst for CO2 Hydrogenation Reaction

2018 ◽  
Vol 16 (1) ◽  
pp. 853-863
Author(s):  
Vivek Srivastava
Keyword(s):  
Hydrogenation Reaction ◽  
Significant Loss ◽  
Co2 Hydrogenation ◽  
Icp Oes ◽  
Structural Morphology ◽  
Tem Analysis ◽  
Catalytic Systems ◽  
Practical Applications ◽  
Highly Active ◽  
Ionic Liquid Medium

AbstractWe developed a series of new organic-inorganic hybrid hydrotalcite functionalized Ru catalytic systems. All the developed materials have been studied by FTIR, N2 physisorption, ICP-OES, XPS, NMR (1H, 13C, 29Si) and TEM analysis were performed to know the physiochemical behavior and structural morphology of functionalized hydrotalcite materials. XPS results strongly suggest that it involves the formation of N-Ru coordination bonds. We applied these well analyzed materials for CO2 hydrogenation reaction as catalyst (with and without ionic liquid medium). We found that Ru metal containing functionalized hydrotalcite materials were highly active and stable (in terms of catalyst leaching and recycling). The heterogeneous catalyst can be easily recovered and reused 8 times without significant loss of catalytic activity and selectivity, which is a better green alternative for practical applications.

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.

Characterisation and performance of three promising heterogeneous catalysts in transesterification of palm oil

2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Wan Isahak ◽  
Manal Ismail ◽  
Jamaliah Jahim ◽  
Jumat Salimon ◽  
Mohd Yarmo
Keyword(s):  
Calcium Oxide ◽  
Palm Oil ◽  
Potassium Hydroxide ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Methyl Esters ◽  
Chemical Properties ◽  
Catalytic Performance ◽  
Product Formation ◽  
Reaction Products

AbstractIn this work, the performance of three heterogeneous catalysts, namely potassium hydroxide/γ-alumina, bulk calcium oxide, and nano-calcium oxide, in comparison with the homogeneous potassium hydroxide was studied in the transesterification of palm oil to produce methyl esters and glycerol. The physical and chemical properties of the heterogeneous catalysts were thoroughly characterised and determined using a number of analytical methods to assess their catalytic activities prior to transesterification. The reaction products were analysed using liquid chromatography and their properties were quantified based on the American Society of Testing and Materials and United State Pharmacopoeia standard methods. At the 65°C reaction temperature, the oil-to-methanol mole ratio of 1: 15, 2.5 h of the reaction time, and catalyst (φ r = 1: 40), potassium hydroxide, potassium hydroxide/γ-alumina, nano-calcium oxide, and bulk calcium oxide gave methyl ester yields of 97 %, 96 %, 94 %, and 90 %, respectively. The impregnation of γ-alumina with potassium hydroxide displayed a catalytic performance comparable with the performance of potassium hydroxide where the former could be physically separated via filtration resulting in a relatively greater purity of products. Other advantages included the longer reusability of the catalyst and more active sites with lower by-product formation.

What catalysis needs from the electron microscopist

1988 ◽  
Vol 46 ◽  
pp. 694-695
Author(s):  
Alexis T. Bell
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Surface Composition ◽  
Internal Surface ◽  
Active Phase ◽  
Atomic Scale ◽  
Metal Catalyst ◽  
Internal Surface Area ◽  
Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

scholarly journals Synergistic Effect of Alkali Na and K Promoter on Fe-Co-Cu-Al Catalysts for CO2 Hydrogenation to Light Hydrocarbons

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 735
Author(s):  
Yuhao Zheng ◽  
Chenghua Xu ◽  
Xia Zhang ◽  
Qiong Wu ◽  
Jie Liu
Keyword(s):  
Synergistic Effect ◽  
Active Sites ◽  
Intermediate Formation ◽  
Active Phase ◽  
Dissociative Adsorption ◽  
Co2 Hydrogenation ◽  
Chain Growth ◽  
Co2 Conversion ◽  
Light Hydrocarbons ◽  
Active Centers

Alkali metal K- and/or Na-promoted FeCoCuAl catalysts were synthesized by precipitation and impregnation, and their physicochemical and catalytic performance for CO2 hydrogenation to light hydrocarbons was also investigated in the present work. The results indicate that Na and/or K introduction leads to the formation of active phase metallic Fe and Fe-Co crystals in the order Na < K < K-Na. The simultaneous introduction of Na and K causes a synergistic effect on increasing the basicity and electron-rich property, promoting the formation of active sites Fe@Cu and Fe-Co@Cu with Cu0 as a crystal core. These effects are advantageous to H2 dissociative adsorption and CO2 activation, giving a high CO2 conversion with hydrogenation. Moreover, electron-rich Fe@Cu (110) and Fe-Co@Cu (200) provide active centers for further H2 dissociative adsorption and O-C-Fe intermediate formation after adsorption of CO produced by RWGS. It is beneficial for carbon chain growth in C2+ hydrocarbons, including olefins and alkanes. FeCoCuAl simultaneously modified by K-Na exhibits the highest CO2 conversion and C2+ selectivity of 52.87 mol% and 89.70 mol%, respectively.

scholarly journals Ultrasound-Assisted Preparation of Mo/ZSM-5 Zeolite Catalyst for Non-Oxidative Methane Dehydroaromatization

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 313
Author(s):  
Heidy Ramirez-Mendoza ◽  
Mafalda Valdez Lancinha Pereira ◽  
Tom Van Gerven ◽  
Cécile Lutz ◽  
Ignacio Julian
Keyword(s):  
Catalytic Activity ◽  
Ion Exchange ◽  
Active Sites ◽  
Chemical Properties ◽  
Successful Implementation ◽  
Metal Dispersion ◽  
Zeolite Framework ◽  
Dispersed Catalysts ◽  
Methane Dehydroaromatization ◽  
Ultrasound Assisted

The activity and selectivity of Mo/ZSM-5, benchmarking catalyst for the non-oxidative dehydroaromatization of methane, strongly depend on the cluster size, spatial distribution, and chemical environment of the Mo-based active sites. This study discloses the use of an ultrasound-assisted ion-exchange (US-IE) technique as an alternative Mo/ZSM-5 synthesis procedure in order to promote metal dispersion along the zeolite framework. For this purpose, a plate transducer (91.8 kHz) is employed to transmit the ultrasonic irradiation (US) into the ion-exchange reactor. The physico-chemical properties and catalytic activity of samples prepared under the said irradiation procedure and traditional impregnation (IWI) method are critically evaluated. Characterization results suggest that US neither affects the crystalline structure nor the particle size of the parent zeolite. However, US-IE promotes molybdenum species dispersion, avoids clustering at the external fresh zeolite surface and enhances molybdate species anchoring to the zeolite framework with respect to IWI. Despite the improved metal dispersion, the catalytic activity between catalysts synthesized by US-IE and IWI is comparable. This suggests that the sole initial dispersion enhancement does not suffice to boost the catalyst productivity and further actions such ZSM-5 support and catalyst pre-conditioning are required. Nevertheless, the successful implementation of US-IE and the resulting metal dispersion enhancement pave the way toward the application of this technique to the synthesis of other dispersed catalysts and materials of interest.

Functionalized silica nanotubes with azo-chromophore for enhanced Pd2+ and Co2+ ions monitoring in E-wastes

2021 ◽  
Vol 329 ◽  
pp. 115585
Author(s):  
Khlood S. Abou-Melha ◽  
Gamil A.A. Al-Hazmi ◽  
Turki M. Habeebullah ◽  
Ismail Althagafi ◽  
Abdullah Othman ◽  
...  
Keyword(s):  
Functionalized Silica ◽  
Silica Nanotubes ◽  
Azo Chromophore
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