scholarly journals Synthesis and Evaluation of ABO3 Perovskites (A=La and B=Mn, Co) with Stoichiometric and Over-stoichiometric Ratios of B/A for Catalytic Oxidation of Trichloroethylene

2018 ◽  
Vol 13 (1) ◽  
pp. 47 ◽  
Author(s):  
Razieh Alagheband ◽  
Sarah Maghsoodi ◽  
Amirhossein Shahbazi Kootenaei ◽  
Hassan Kianmanesh
Keyword(s):  
Catalytic Oxidation ◽  
Fixed Bed ◽  
Combustion Method ◽  
Catalytic Performance ◽  
Lanthanum Manganite ◽  
Fixed Bed Reactor ◽  
Bet Surface Area ◽  
Manganite Perovskite ◽  
Different Temperatures ◽  
Stoichiometric Ratios

In this contribution, perovskite catalysts (ABO3) were probed that site A and site B were occupied by lanthanum and transition metals of manganese or cobalt, respectively, with stoichiometric ratios as well as 20 % over-stoichiometric ratios of B/A. The perovskite samples were synthesized using a gel-combustion method and characterized by BET, XRD, SEM and O2-TPD analyses. After mounting in a fixed bed reactor, the catalysts were examined in atmospheric pressure conditions at different temperatures for oxidation of 1000 ppm trichloroethylene in the air. Evaluation of over-stoichiometric catalysts activity showed that the increased ratio of B/A in the catalysts compared to the stoichiometric one led to BET surface area, oxygen mobility, and consequently catalytic performance improvement. The lanthanum manganite perovskite with 20 % excess manganese yielded the best catalytic performance among the probed perovskites. Copyright © 2018 BCREC Group. All rights reservedReceived: 28th April 2017; Revised: 31st July 2017; Accepted: 4th August 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018How to Cite: Alagheband, R., Maghsoodi, S., Kootenaei, A.S., Kianmanesh, H. (2018). Synthesis and Evaluation of ABO3 Perovskites (A=La and B=Mn, Co) with Stoichiometric and Over-stoichiometric Ratios of B/A for Catalytic Oxidation of Trichloroethylene. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 47-56 (doi:10.9767/bcrec.13.1.1188.47-56) 

scholarly journals HYDROGEN PRODUCTION FROM ETHANOL DRY REFORMING OVER LANTHANIA-PROMOTED Co/Al2O3 CATALYST

2018 ◽  
Vol 19 (1) ◽  
pp. 24-33 ◽  
Author(s):  
FAHIM FAYAZ ◽  
NGUYEN THI ANH NGA ◽  
THONG LE MINH PHAM ◽  
HUONG THI DANH ◽  
BAWADI ABDULLAH ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Fixed Bed ◽  
Product Yield ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Bet Surface Area ◽  
Impregnation Method ◽  
X Ray ◽  
Co2 Partial Pressure ◽  
La Addition

La-promoted and unpromoted 10%Co/Al2O3 catalysts were synthesized using wet a impregnation method and evaluated in a quartz fixed-bed reactor at different CO2:C2H5OH ratios of 2.5:1-1:2.5 and a reaction temperature of 973 K under atmospheric pressure. X-ray diffraction measurements detected the presence of Co3O4 and CoAl2O4 phases on the surface of both promoted and unpromoted catalysts. BET surface area of promoted and unpromoted 10%Co/Al2O3 catalysts was about 143.09 and 136.04 m2.g-1, respectively. The La promoter facilitated Co3O4 reduction, improved the degree of reduction from 86 to 98% and increased metal dispersion from 9.11% to 16.64%. The La-promoted catalyst appeared to be a better catalyst in terms of catalytic activity and product yield regardless of reactant partial pressure. Both C2H5OH and CO2 conversions improved significantly with an increase in CO2 partial pressure from 20 to 50 kPa for both catalysts whilst a decline in catalytic performance was observed with rising C2H5OH partial pressure. La addition improved C2H5OH and CO2 conversions up to about 74.22% and 33.80%, respectively. ABSTRAK: Penggalak-La dan bukan penggalak-La mangkin 10%Co/Al2O3 dihasilkan menggunakan kaedah impregnasi basah dan dinilai dalam reaktor alas-tetap quarza pada pelbagai nisbah CO2:C2H5OH sebanyak 2.5:1-1:2.5 dan suhu tindak balas sebanyak 973 K di bawah tekanan atmosfera. Hasil daripada ukuran pembelauan X-ray, didapati terdapat kehadiran fasa Co3O4 dan CoAl2O4 pada permukaan kedua-dua mangkin penggalak dan bukan penggalak. Permukaan kawasan BET pada penggalak dan bukan penggalak mangkin 10%Co/Al2O3 adalah masing-masing sebanyak 143.09 dan 136.04 m2.g-1. Penggalak-La membantu dalam pengurangan Co3O4,membaiki peratus penurunan daripada 86 kepada 98% dan menambah penyebaran logam daripada 9.11% kepada 16.64%. Mangkin penggalak-La dilihat sebagai mangkin terbaik dari segi aktiviti pemangkinan dan hasil pengeluaran, biarpun pada tekanan separa reaktan. Kedua-dua penukaran C2H5OH dan CO2 meningkat dengan ketara dengan kenaikan separa tekanan CO2 daripada 20 kepada 50 kPa bagi kedua-dua pemangkin, sementara penurunan dalam aktiviti pemangkinan dilihat dengan kenaikan tekanan separa C2H5OH. Penambahan La meningkatkan penukaran C2H5OH dan CO2, masing-masing sebanyak 74.22% dan 33.80%.

CO2 valorization into synthetic natural gas (SNG) using a Co–Ni bimetallic Y2O3 based catalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Radwa A. El-Salamony ◽  
Sara A. El-Sharaky ◽  
Seham A. Al-Temtamy ◽  
Ahmed M. Al-Sabagh ◽  
Hamada M. Killa
Keyword(s):  
Reaction Mechanism ◽  
Natural Gas ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Synthetic Natural Gas ◽  
Methanation Reaction ◽  
Co2 Valorization

Abstract Recently, because of the increasing demand for natural gas and the reduction of greenhouse gases, interests have focused on producing synthetic natural gas (SNG), which is suggested as an important future energy carrier. Hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. Nickel supported on yttrium oxide and promoted with cobalt were prepared by the wet-impregnation method respectively and characterized using SBET, XRD, FTIR, XPS, TPR, and HRTEM/EDX. CO2 hydrogenation over the Ni/Y2O3 catalyst was examined and compared with Co–Ni/Y2O3 catalysts, Co% = 10 and 15 wt/wt. The catalytic test was conducted with the use of a fixed-bed reactor under atmospheric pressure. The catalytic performance temperature was 350 °C with a supply of H2:CO2 molar ratio of 4 and a total flow rate of 200 mL/min. The CH4 yield was reached 67%, and CO2 conversion extended 48.5% with CO traces over 10Co–Ni/Y2O3 catalyst. This encourages the direct methanation reaction mechanism. However, the reaction mechanism over Ni/Y2O3 catalyst shows different behaviors rather than that over bi-metal catalysts, whereas the steam reforming of methane reaction was arisen associated with methane consumption besides increase in H2 and CO formation; at the same temperature reaction.

scholarly journals Performance Analysis of TiO2-Modified Co/MgAl2O4 Catalyst for Dry Reforming of Methane in a Fixed Bed Reactor for Syngas (H2, CO) Production

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3347
Author(s):  
Arslan Mazhar ◽  
Asif Hussain Khoja ◽  
Abul Kalam Azad ◽  
Faisal Mushtaq ◽  
Salman Raza Naqvi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Dry Reforming ◽  
Fixed Bed Reactor ◽  
Dry Reforming Of Methane ◽  
Catalyst Stability ◽  
Feed Ratio ◽  
Catalyst Loading ◽  
Impregnation Method

Co/TiO2–MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2–MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2–MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2–MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2–MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieved H2/CO ratio of 0.9 was due to the excess amount of CO produced because of the higher conversion rate of CO2 and the surface carbon reaction with oxygen species. Furthermore, in a time on stream (TOS) test, the catalyst exhibited 75 h of stability with significant catalytic activity. Catalyst potential lies in catalyst stability and performance results, thus encouraging the further investigation and use of the catalyst for the long-run DRM process.

scholarly journals Effect of CO2 partial pressure on dry reforming of ethanol for hydrogen production

2018 ◽  
Vol 1 (1) ◽  
pp. 6-10
Author(s):  
Fahim Fayaz ◽  
Ahmad Ziad Sulaiman ◽  
Sharanjit Singh ◽  
Sweeta Akbari
Keyword(s):  
Partial Pressure ◽  
Fixed Bed ◽  
Dry Reforming ◽  
Fixed Bed Reactor ◽  
Bet Surface Area ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Co2 Partial Pressure ◽  
Temperature Programmed ◽  
Al2o3 Catalyst

The effect of CO2 partial pressure on ethanol dry reforming was evaluated over 5%Ce-10%Co/Al2O3 catalyst at = PCO2 = 20-50 kPa, PC2H5OH = 20 kPa, reaction temperature of 973 K under atmospheric pressure. The catalyst was prepared by using impregnation method and tested in a fixed-bed reactor. X-ray diffraction measurements studied the formation of Co3O4, spinel CoAl2O4 and CeO2, phases on surface of 5%Ce-10%Co/Al2O3 catalyst. CeO2, CoO and Co3O4 oxides were obtained during temperature–programmed calcination. Ce-promoted 10%Co/Al2O3 catalyst possessed high BET surface area of 137.35 m2 g-1. C2H5OH and CO2 conversions was improved with increasing CO2 partial pressure from 20-50 kPa whilst the optimal selectivity of H2 and CO was achieved at 50 kPa.

On efficiency of vanadium-oxide promoter in cobalt Fischer – Tropsch catalysts

2021 ◽  
Vol 1 (1-2) ◽  
pp. 15
Author(s):  
Elham Yaghoobpour ◽  
Yahya Zamani ◽  
Saeed Zarrinpashne ◽  
Akbar Zamaniyan
Keyword(s):  
Vanadium Oxide ◽  
Active Sites ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bet Surface Area ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Co Conversion ◽  
Loading Amount

Promoters and their loading amount have crucial roles in cobalt Fischer – Tropsch catalysts. In this regard, the effects of vanadium oxide (V2O5) as a proposed promoter for Co catalyst supported on TiO2 have been investigated. Three catalysts with 0, 1, and 3 wt.% of V2O5 promoter loading are prepared by the incipient wetness impregnation method, and characterized by the BET surface area analyzer, XRD, H2-TPR, and TEM techniques. The fixed-bed reactor was employed for their evaluations. It was found that the catalyst containing 1 wt.% V2O5 has the best performance among the evaluated catalysts, demonstrating remarkable selectivity: 92 % C5+ and 5.7 % CH4, together with preserving the amount of CO conversion compared to the unpromoted catalyst. Furthermore, it is reported that the excess addition of V2O5 promoter (> 1 wt.%) in the introduced catalyst leads to the detrimental effect on the CO conversion and C5+ selectivity, mainly owing to diminished active sites by V2O5 loading.

scholarly journals Pt-Promoted Tungsten Carbide Nanostructures on Mesoporous Pinewood-Derived Activated Carbon for Catalytic Oxidation of Formaldehyde at Low Temperatures

2020 ◽  
Vol 1 (2) ◽  
pp. 86-105
Author(s):  
Qiangu Yan ◽  
Zhiyong Cai
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Relative Humidity ◽  
Tungsten Carbide ◽  
Catalytic Oxidation ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Inert Atmosphere ◽  
Bet Surface Area ◽  
Formaldehyde Concentration

Tungsten carbide (WC) nanostructures were prepared by carbothermal reduction (CR) of tungsten-impregnated pinewood-derived activated carbon (AC) at 1000 °C under an inert atmosphere. Brunauer-Emmet-Teller (BET) surface area, pore structures of the AC, and catalyst samples were evaluated by N2 adsorption-desorption experiments. The structures of the catalysts were characterized using X-ray powder diffraction (XRD). The morphologies and particle structures of the synthesized WC nanoparticles were investigated by field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The WC/AC material was used as support of the platinum catalysts for catalytic oxidation of formaldehyde (HCHO) from interior sources. Pt-WC/AC catalysts with different platinum loadings were assessed for the catalytic oxidation of HCHO at low temperature. The catalytic performance was found to be significantly influenced by reaction temperature, initial formaldehyde concentration, relative humidity, and space velocity. The testing results demonstrated that HCHO can be totally oxidized by the 1 wt% Pt-WC/AC catalyst in the gas hourly space velocity (GHSV) = 50,000 h−1 at 30 °C with a relative humidity (RH) of 40%.

scholarly journals Hierarchical H-ZSM5 zeolites based on natural kaolinite as a high-performance catalyst for methanol to aromatic hydrocarbons conversion

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmad Asghari ◽  
Mohammadreza Khanmohammadi Khorrami ◽  
Sayed Habib Kazemi
Keyword(s):  
Pore Size ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Low Cost ◽  
Direct Synthesis ◽  
Fixed Bed ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Good Prospect

AbstractThe present work introduces a good prospect for the development of hierarchical catalysts with excellent catalytic performance in the methanol to aromatic hydrocarbons conversion (MTA) process. Hierarchical H-ZSM5 zeolites, with a tailored pore size and different Si/Al ratios, were synthesized directly using natural kaolin clay as a low-cost silica and aluminium resource. Further explored for the direct synthesis of hierarchical HZSM-5 structures was the steam assisted conversion (SAC) with a cost-effective and green affordable saccharide source of high fructose corn syrup (HFCS), as a secondary mesopore agent. The fabricated zeolites exhibiting good crystallinity, 2D and 3D nanostructures, high specific surface area, tailored pore size, and tunable acidity. Finally, the catalyst performance in the conversion of methanol to aromatic hydrocarbons was tested in a fixed bed reactor. The synthesized H-ZSM5 catalysts exhibited superior methanol conversion (over 100 h up to 90%) and selectivity (over 85%) in the methanol conversion to aromatic hydrocarbon products.

Preparation and Performance of Several Non-Precious Metal Oxides Catalysts for the Low Temperature SCR of NOx with NH3

2011 ◽  
Vol 356-360 ◽  
pp. 1528-1534
Author(s):  
Wei Fang Dong
Keyword(s):  
Low Temperature ◽  
Metal Oxides ◽  
Flue Gas ◽  
Precious Metal ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Low Temperature Scr ◽  
Scr Of Nox

A series of non-precious metal oxides catalysts were prepared for low-temperature selective catalytic reduction (SCR) of NOx with NH3 in a fixed bed reactor. The catalytic performance was evaluated by the removal efficiency of NOx and N2selectivity which were respectively detected by flue gas analyzer and flue gas chromatograph. Furthermore, the components of gas products from the above experiments were analysed with 2010 GC-MS. The results illustrated that the MnO2exhibited the highest NOx conversion to 95.46% and the highest selectivity of N2to 100% at temperature of 393K, then followed ZrO2, Al2O3and Fe2O3.

Effect of Catalyst Synthesis Parameters on the Performance of CO2 Hydrogenation to Methanol over SBA-15 Supported Cu/ZnO-Based Catalysts

2020 ◽  
Vol 400 ◽  
pp. 159-169
Author(s):  
Sara F.H. Tasfy ◽  
Noor Asmawati Mohd Zabidi ◽  
Maizatul Shima Shaharun ◽  
Duvvria Subbarao
Keyword(s):  
Surface Area ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bet Surface Area ◽  
Methanol Production ◽  
Synthesis Conditions ◽  
Metal Loading ◽  
Synthesis Parameters ◽  
Metal Support Interaction ◽  
Active Metal

Bimetallic Cu-ZnO-based catalyst were systematically prepared via impregnation technique under controlled synthesis conditions of active metal loading, ratio of active metal Cu:Zn and synthesis pH. The effect of the synthesis condition on the performance of the Cu-ZnO supported catalysts with respect to the hydrogenation of CO2 to methanol in micro-activity fixed-bed reactor at 250°C, 2.25 MPa, and 75% H2/25%CO2 ratio. The synthesized catalysts were characterized by transmission electron microscopy (TEM) and temperature programmed desorption, reduction, oxidation and pulse chemisorption (TPDRO) and the surface area determination was also performed. The results demonstrate that the catalytic structure, activity, and methanol selectivity was strongly affected by the synthesis parameters. Increasing of synthesis pH from 1 to 7 shows better metal particles distribution, Cu desperation of 29%, higher BET surface area as well as Cu surface area, while further increasing on pH revealed on particles agglomeration and weak metal-support interaction. In addition, increasing of the active metal loading from 5 to 15 % resulted in dramatic increase in the conversion of CO2 and methanol production while further increase caused lower catalytic performance. Moreover, catalyst with total loading of 15%, Cu:Zn ratio of 70:30 synthesized at pH of 7 exhibit higher catalytic activity of 14%, methanol selectivity of 92%, and TOF of 1.24×103 s-1 compared with other catalyst prepared under various conditions

Effect of Ni/Co Ratio on Bimetallic Oxide Supported Silica Catalyst in CO2 Methanation

2015 ◽  
Vol 802 ◽  
pp. 431-436
Author(s):  
Siti Aminah Md Ali ◽  
Ku Halim Ku Hamid ◽  
Kamariah Noor Ismail
Keyword(s):  
Catalytic Activity ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Wet Impregnation ◽  
Co Precipitation

Five series of silica supported bimetallic oxide (NiCo/SiO2) catalysts have been synthesized through successive reverse co-precipitation and wet impregnation methods at different metal loadings (i.e. 80Ni20Co/SiO2,, 60Ni40Co/SiO2,50Ni50Co/SiO2,40Ni60Co/SiO2,20Ni80Co/SiO2). The catalytic performance of these catalysts were tested for the CO2methanation catalysis using microactivity fixed bed reactor. Nickel rich catalyst (80Ni20Co/SiO2) exhibited the highest catalytic activity in the CO2methanation with 47.1% of CO2conversion. Meanwhile, the CH4selectivity and yield was found to be at 99.9% and 27%, respectively.

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