scholarly journals Defect-Rich Nickel Nanoparticles Supported on SiC Derived from Silica Fume with Enhanced Catalytic Performance for CO Methanation

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 295 ◽  
Author(s):  
Qi Song ◽  
Xingwu Zhai ◽  
Feng Yu ◽  
Jiangbing Li ◽  
Xin Ren ◽  
...  
Keyword(s):  
Silica Fume ◽  
Density Functional ◽  
Co Adsorption ◽  
Space Velocity ◽  
Catalytic Performance ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
Ni Nanoparticles ◽  
Metal Support Interaction ◽  
Metal Support

With the increased demands of environmental protection, recycling/utilization of industrial byproducts has attracted much attention from both industry and academic communities. In this work, silicon carbide (SiC) was successfully synthesized from industrial waste silica fume (SF) during metallic silicon production. Following this, Ni nanoparticles with many defects were supported on the as-obtained SiC by conventional impregnation method. The results showed that defect-rich Ni nanoparticles were dispersed onto the surface of SiC. The as-obtained Ni/SF-SiC exhibited an enhanced metal-support interaction between Ni and SiC. Furthermore, the density functional theory (DFT) calculations showed that the H2 and CO adsorption energy on Ni vacancy (VNi) sites of Ni/SF-SiC were 1.84 and 4.88 eV, respectively. Finally, the Ni/SF-SiC performed high catalytic activity with CO conversion of 99.1% and CH4 selectivity of 85.7% at 350 °C, 0.1 MPa and a gas hourly space velocity (GHSV) of 18,000 mL·g−1·h−1. Moreover, Ni/SF-SiC processed good catalytic stability in the 50 h continuous reaction.

Activity of yFe-10Cu/H-Sep and xCu/H-Sep for the Selective Catalytic Reduction of NO with Propylene

2012 ◽  
Vol 518-523 ◽  
pp. 281-284
Author(s):  
Qing Ye ◽  
Hai Ping Wang ◽  
Hai Xia Zhao ◽  
Shui Yuan Cheng ◽  
Tian Fang Kang
Keyword(s):  
Catalytic Reduction ◽  
Catalytic Performance ◽  
High Dispersion ◽  
High Catalytic Activity ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Promotional Effect ◽  
Scr Of No ◽  
Metal Support Interaction ◽  
Metal Support

Cu supported on acid-treated sepiolite catalysts (xCu/H-Sep, x = 0  20.0 wt%) or Cu-Fe mixed supported on acid-treated sepiolite catalysts (yFe-10Cu/H-Sep, y = 0  20.0 wt%) were prepared by the incipient wetness impregnation method. The xCu/H-Sep and yFe-10Cu/H-Sep catalysts were characterized by means of XRD, BET, XRF, XPS, and H2-TPR techniques, and their catalytic activities were evaluated for the SCR of NO with propylene. XPS and XRD results indicate that there was the co-presence of Cu+-Cu2+ and Fe2+-Fe3+ over the surfaces of yFe-10Cu/H-Sep catalysts, and there was a strong interaction between Cu, Fe and sepiolite. High promotional effect of iron additive on the catalytic performance of Cu/H-Sep catalyst were found in C3H6-SCR of NO reaction. The highest activity of 65% NO conversion was obtained over 15Fe-10Cu/H-Sep catalyst at 280 oC under the condition of 1000 ppm NO, 1000 ppm C3H6, and 5% O2. The high catalytic activity of 15Fe-10Cu/H-Sep catalyst for NO reduction was due to its high reducibility to activate C3H6 to selectively reduce NO in the presence of excess O2. The high dispersion of copper oxides and strong metal-support interaction over 15Fe-10Cu/H-Sep catalyst also improve its catalytic performance.

Direct Dehydrogenation of n-Butane Over Pt/Sn/Zn/γ-Al2O3 Nano-Catalyst: Effect of Zn Content

2015 ◽  
Vol 15 (10) ◽  
pp. 8318-8323
Author(s):  
Hyun Seo ◽  
Jong Kwon Lee ◽  
Ung Gi Hong ◽  
Gle Park ◽  
Yeonshick Yoo ◽  
...  
Keyword(s):  
Surface Area ◽  
Zinc Content ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
Support Interaction ◽  
Nano Catalyst ◽  
Metal Support Interaction ◽  
Zn Content ◽  
Metal Support ◽  
Nano Catalysts

A series of Pt/Sn/XZn/γ-Al2O3 nano-catalysts with different Zn content (X = 0, 0.25, 0.5, 0.75, and 1.0 wt%) were prepared by a sequential impregnation method. They were applied to the direct dehydrogenation of n-butane to n-butene and 1,3-butadiene. The effect of zinc content of Pt/Sn/XZn/γ-Al2O3 nano-catalysts on their physicochemical properties and catalytic activities in the direct dehydrogenation of n-butane was investigated. The catalytic performance of Pt/Sn/XZn/γ-Al2O3 nano-catalysts strongly depended on zinc content. Among the catalysts tested, Pt/Sn/0.5Zn/γ-Al2O3 nano-catalyst showed the best catalytic performance in terms of yield for total dehydrogenation products (TDP, n-butene and 1,3-butadiene). TPR (temperature-programmed reduction) and H2-chemisorption experiments were carried out to measure metal-support interaction and Pt surface area of the catalysts. Experimental results revealed that metal-support interaction and Pt surface area of the catalysts were closely related to the catalytic performance. Yield for TDP increased with increasing metal-support interaction and Pt surface area of the catalysts.

Isomorphic titanium-substituted mesoporous SBA-16 as support for cobalt Fischer–Tropsch synthesis catalysts: Balance between dispersion and reduction

2021 ◽  
Author(s):  
Liang Wei ◽  
Jian Chen ◽  
Shuai Lyu ◽  
Chengchao Liu ◽  
Yanxi Zhao ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Support Interaction ◽  
Delicate Balance ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Synthesis Catalysts

The delicate balance between dispersion and reduction of the Co-based Fischer–Tropsch synthesis catalyst is the golden key to enhancing catalytic performance, which highly depends on an optimized metal–support interaction. In...

Zn2+ stabilized Pd clusters with enhanced covalent metal–support interaction via the formation of Pd–Zn bonds to promote catalytic thermal stability

Nanoscale ◽  
2020 ◽  
Vol 12 (27) ◽  
pp. 14825-14830
Author(s):  
Kai-Qiang Jing ◽  
Yu-Qing Fu ◽  
Zhi-Qiao Wang ◽  
Zhe-Ning Chen ◽  
Hong-Zi Tan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Adsorption Energy ◽  
Catalytic Performance ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Pd Clusters

Zn2+-Modified MgAl-LDH with ultra-low Pd cluster loading was synthesized. The higher adsorption energy and strong covalent metal–support interaction via forming Pd–Zn bonds over Pd/ZnMgAl-LDH account for the robust catalytic performance.

Effects of Cu and K Promoters on the Catalytic Performance of Iron-Based Nanocatalyst for Fischer-Tropsch Synthesis

2013 ◽  
Vol 832 ◽  
pp. 15-20 ◽  
Author(s):  
Sara Faiz Hanna Tasfy ◽  
Noor Asmawati Mohd Zabidi ◽  
Duvvuri Subbarao
Keyword(s):  
Atmospheric Pressure ◽  
Fixed Bed ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Reactant Ratio ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Heavy Hydrocarbons ◽  
Co Conversion ◽  
Iron Based

Iron-based nanocatalyst was prepared via impregnation method on SiO2 support. The effects of promoters, namely, K and Cu, on the physical properties and catalytic performance in FTS have been investigated. The FTS performance of the synthesized nanocatalysts was examined in a fixed-bed microreactor at temperature of 523K, atmospheric pressure, 1.5 reactant ratio (H2/CO) and space velocity of 3L/g-cat.h. In FTS reaction, Cu promoter resulted in a lower CO conversion and C5+ hydrocarbons selectivity but higher selectivity to the lighter hydrocarbons (C1-C4) comparedto those obtained using the K promoter. Higher CO conversion (28.9%) and C5+ hydrocarbons selectivity (54.4%) were obtained using K as a promoter compared to that of Cu promoter. However, the K-promoted nanocatalyst resulted in a lower CO conversion but higher selectivity of the heavy hydrocarbons (C5+) compared to those obtained using the un-promoted nanocatalyst.

scholarly journals Ag/CeO2 Composites for Catalytic Abatement of CO, Soot and VOCs

Catalysts ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 285 ◽  
Author(s):  
M. Grabchenko ◽  
N. Mikheeva ◽  
G. Mamontov ◽  
M. Salaev ◽  
L. Liotta ◽  
...  
Keyword(s):  
Noble Metals ◽  
Chemical Properties ◽  
Soot Oxidation ◽  
Catalytic Performance ◽  
Defective Structure ◽  
Metal Support Interaction ◽  
Key Factor ◽  
Metal Support ◽  
Vocs Abatement

Nowadays catalytic technologies are widely used to purify indoor and outdoor air from harmful compounds. Recently, Ag–CeO2 composites have found various applications in catalysis due to distinctive physical-chemical properties and relatively low costs as compared to those based on other noble metals. Currently, metal–support interaction is considered the key factor that determines high catalytic performance of silver–ceria composites. Despite thorough investigations, several questions remain debating. Among such issues, there are (1) morphology and size effects of both Ag and CeO2 particles, including their defective structure, (2) chemical and charge state of silver, (3) charge transfer between silver and ceria, (4) role of oxygen vacancies, (5) reducibility of support and the catalyst on the basis thereof. In this review, we consider recent advances and trends on the role of silver–ceria interactions in catalytic performance of Ag/CeO2 composites in low-temperature CO oxidation, soot oxidation, and volatile organic compounds (VOCs) abatement. Promising photo- and electrocatalytic applications of Ag/CeO2 composites are also discussed.

scholarly journals NiMo-sulfide supported on activated carbon to produce renewable diesel

2017 ◽  
Vol 22 (1) ◽  
pp. 71 ◽  
Author(s):  
Juan Tapia ◽  
Nancy Y Acelas ◽  
Diana López ◽  
Andrés Moreno
Keyword(s):  
Activated Carbon ◽  
Batch Reactor ◽  
Liquid Hydrocarbon ◽  
Product Distribution ◽  
Impregnation Method ◽  
Carbon Supports ◽  
Gaseous Products ◽  
Oxygenated Compounds ◽  
Metal Support Interaction ◽  
Metal Support

Due to their weak polarity and large surface area, activated carbon supports have the potential to enhance the dispersion of metal-sulfides. It is expected that the absence of a strong metal-support interaction can result in the formation of a very active and stable Ni-Mo-S phase. In this study, catalysts with different amounts of nickel and molybdenum supported on a commercial activated carbon were prepared by a co-impregnation method and characterized by BET, XRF, and SEM techniques. The catalytic activity for hydroprocessing of Jatropha oil was evaluated in a batch reactor, and the composition of the liquid and gaseous products were determined. Results showed that gaseous products are mainly composed of high amounts of propane and small amounts of other light hydrocarbons (C1 to C5). Liquid hydrocarbon products consisted of a mixture containing mainly n-paraffins of C15-C18 and some oxygenated compounds. The catalysts with a mass fraction<br />of 3 % Ni, 15 % Mo (Ni3Mo15/AC) presented the highest selectivity toward C17-C18 hydrocarbons, with a product distribution similar to a commercial<br />alumina-supported Ni-Mo-S catalyst.

scholarly journals Catalytic Oxidation of Chlorobenzene over Pd-TiO2 /Pd-Ce/TiO2 Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 347 ◽  
Author(s):  
Wenjun Liang ◽  
Xiaoyan Du ◽  
Yuxue Zhu ◽  
Sida Ren ◽  
Jian Li
Keyword(s):  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Calcination Temperature ◽  
Catalyst Activity ◽  
Space Velocity ◽  
Impregnation Method ◽  
Tio2 Catalyst ◽  
Metal Support ◽  
Oxidation Efficiency

A series of Pd-TiO2/Pd-Ce/TiO2 catalysts were prepared by an equal volume impregnation method. The effects of different Pd loadings on the catalytic activity of chlorobenzene (CB) were investigated, and the results showed that the activity of the 0.2%-0.3% Pd/TiO2 catalyst was optimal. The effect of Ce doping enhanced the catalytic activity of the 0.2% Pd-0.5% Ce/TiO2 catalyst. The characterization of the catalysts using BET, TEM, H2-TPR, and O2-TPD showed that the oxidation capacity was enhanced, and the catalytic oxidation efficiency was improved due to the addition of Ce. Ion chromatography and Gas Chromatography-Mass Spectrometer results showed that small amounts of dichlorobenzene (DCB) and trichlorobenzene (TCB) were formed during the decomposition of CB. The results also indicated that the calcination temperature greatly influenced the catalyst activity and a calcination temperature of 550 °C was the best. The concentration of CB affected its decomposition, but gas hourly space velocity had little effect. H2-TPR indicated strong metal–support interactions and increased dispersion of PdO in the presence of Ce. HRTEM data showed PdO with a characteristic spacing of 0.26 nm in both 0.2% Pd /TiO2 and 0.2% Pd-0.5% Ce/TiO2 catalysts. The average sizes of PdO nanoparticles in the 0.2% Pd/TiO2 and 0.2% Pd-0.5% Ce/TiO2 samples were 5.8 and 4.7 nm, respectively. The PdO particles were also deposited on the support and they were separated from each other in both catalysts.

scholarly journals Stability of heterogeneous single-atom catalysts: a scaling law mapping thermodynamics to kinetics

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Ya-Qiong Su ◽  
Long Zhang ◽  
Yifan Wang ◽  
Jin-Xun Liu ◽  
Valery Muravev ◽  
...  
Keyword(s):  
Metal Atom ◽  
Density Functional ◽  
Activation Barrier ◽  
Scaling Law ◽  
Precious Metals ◽  
Catalytic Performance ◽  
Single Atom ◽  
Atom Diffusion ◽  
Computational Screening ◽  
Metal Support

Abstract Heterogeneous single-atom catalysts (SACs) hold the promise of combining high catalytic performance with maximum utilization of often precious metals. We extend the current thermodynamic view of SAC stability in terms of the binding energy (Ebind) of single-metal atoms on a support to a kinetic (transport) one by considering the activation barrier for metal atom diffusion. A rapid computational screening approach allows predicting diffusion barriers for metal–support pairs based on Ebind of a metal atom to the support and the cohesive energy of the bulk metal (Ec). Metal–support combinations relevant to contemporary catalysis are explored by density functional theory. Assisted by machine-learning methods, we find that the diffusion activation barrier correlates with (Ebind)2/Ec in the physical descriptor space. This diffusion scaling-law provides a simple model for screening thermodynamics to kinetics of metal adatom on a support.

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