Analisis Struktur dan Spesies Permukaan Terhadap Kereaktifan Mangkin Oksida Mangan–Timah

2012 ◽  
Author(s):  
Mohd. Tahir Ahmad ◽  
Wan Azelee Wan Abu Bakar ◽  
Nor Aziah Buang
Keyword(s):  
Manganese Oxides ◽  
Fixed Bed ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
Catalyst Sample ◽  
Calcination Temperatures ◽  
Composition Ratios ◽  
The Relationship ◽  
Micro Reactor

Oksida timah (IV) dengan kehadiran bahan pendop memperlihatkan pelbagai aktiviti yang menarik untuk dikaji dengan mendalam. Dalam kajian ini oksida timah (IV) didopkan dengan Mn(II) dan Mn(IV) pada pelbagai nisbah komposisi dan suhu pengkalsinan menggunakan kaedah pengisitepuan. Bagi melihat aktiviti pemangkinan, sampel mangkin diuji menggunakan sistem reaktor mikro padatan tetap yang menghampiri keadaan sebenar ekzos kenderaan bermotor. Hasil ujian menunjukkan sampel mangkin yang didopkan dengan Mn(II) pada nisbah komposisi 40:60 berpotensi sebagai mangkin dua arah yang setanding dengan mangkin komersil, Pt/AI2O3 dan Hopcalite (CuMn2O4). Pengoksidaan lengkap 100% (T100) berlaku pada suhu yang rendah iaitu T100 = 100°C bagi gas CO dan T100 = 300°C bagi gas propana. Bagi memahami kaitan struktur dan keupayaan pemangkinan sampel mangkin, dua teknik pencirian dilakukan iaitu XPS dan XRD. Pencirian melalui teknik XPS mengenalpasti oksida mangan wujud dengan nombor pengoksidaan +2 dan +3 pada suhu pengkalsinan 400 dan 600°C. Kewujudan nombor pengoksidaan tersebut disahkan melalui teknik XRD iaitu bagi oksida mangan disumbang oleh Mn2O3 dan spinel Mn3O4. Didapati aktiviti pemangkinan yang terbaik bagi sampel mangkin ialah apabila sampel mangkin berada dalam percampuran kedua–dua nombor pengoksidaan tersebut. Daripada teknik XRD juga didapati darjah kehabluran sampel mangkin meningkat apabila suhu pengkalsinan ditingkatkan. Kata kunci: Aktiviti pemangkinan; XPS dan XRD Tin(IV) oxide when doped with other metal oxides exhibit interesting activities to be studied further. In this research, tin(IV) oxide was doped with Mn(II) and Mn(IV) at various composition ratios and calcination temperatures using an impregnation method. The catalytic performance of the prepared sample were investigated using a fixed bed micro-reactor system which resembled the actual exhaust gas condition. For catalyst sample doped with Mn(II) 40:60, the catalytic results have shown their potential as 2–way catalyst that are comparable with the commercial catalyst (Pt/AI2O3 and Hopcalite (CuMn2O4). Catalyst sample gave a 100% conversion (T100) at a low temperature of T100 = 100°C for CO and T100 of 300 for C3H8. To verify the relationship between the structures of the catalyst sample with their catalytic capabilities, characterisation analysis by XPS and XRD were performed. XPS analysis recalled the existence of manganese oxides with oxidation numbers of +2 and +3 at calcination temperatures of 400 and 600°C. This finding is supported by XRD analysis which showed that the manganese oxide was contributed by Mn2O3 and spinel Mn3O4. Therefore the best catalytic activities could be achieved with a catalyst sample prepared under a mixture of the two oxidation numbers. More over from the XRD technique, the degree of crystalinity of the catalyst sample increase as the calcination temperature increases. Key words: Catalytic activity; XPS and XRD

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.

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 Hydrogen Production From Steam Gasification of Palm Kernel Shell Using Sequential Impregnation Bimetallic Catalysts

2021 ◽  
Vol 14 ◽  
pp. 58-62
Author(s):  
Anita Ramli ◽  
Siti Eda Eliana Misi ◽  
Mas Fatiha Mohamad ◽  
Suzana Yusup
Keyword(s):  
Catalytic Activity ◽  
Fixed Bed ◽  
Palm Kernel ◽  
Steam Gasification ◽  
Impregnation Method ◽  
Ni Catalysts ◽  
Palm Kernel Shell ◽  
Calcination Temperatures ◽  
Zeolite Β ◽  
Metal Addition

Zeolite β supported bimetallic Fe and Ni catalysts have been prepared using sequential impregnation method and calcined at temperatures between 500-700 ºC. The catalytic activity of these catalysts in a steam gasification of palm kernel shell was tested in a fixed-bed quartz micro-reactor at 700 ºC. Both Fe and Ni active metals present in FeNi/BEA and NiFe/BEA catalysts are corresponding to Fe2O3 and NiO. Different calcination temperatures and different sequence in metal addition have a significant effect to the catalytic activity where FeNi/BEA (700) shows the highest hydrogen produced than other catalysts.

scholarly journals Effects of Al and Co Promoters on CuO/SBA-15/Kaolinite Catalyst Properties and CO2 Hydrogenation at Low Pressure

2021 ◽  
Vol 259 ◽  
pp. 04001
Author(s):  
Zane Abelniece ◽  
Valdis Kampars ◽  
Helle-Mai Piirsoo ◽  
Aile Tamm
Keyword(s):  
Fixed Bed ◽  
Mesoporous Structure ◽  
Xrd Analysis ◽  
Hydrogenation Reaction ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Kaolinite Clay ◽  
Post Synthesis ◽  
Adsorption Desorption ◽  
Hydrogenation Of Co

CuO on mesoporous silica catalyst was prepared with post synthesis impregnation method, and the effects of Al and Co promoters on CuO/SBA-15/kaolinite catalyst properties and CO2 hydrogenation were studied. The mixing technology with kaolinite clay (containing Al2O3) was used to obtain the granules and to enhance the CO2 conversion to methanol as a product. The performance of all catalysts for catalytic hydrogenation of CO2 was evaluated on a fixed-bed tubular micro-activity reactor at 20 bar and 250°C with H2/CO2 molar ratio 3:1. XRD analysis, N2 adsorption-desorption analysis and SEM-EDX analysis indicated that the mesoporous structure of SBA-15 remains after loading with CuO and promoters, and after mixing with kaolinite clay. Results were compared with results obtained with commercial CuO/Al2O3 catalyst, which showed high MeOH selectivity (78%) during CO2 hydrogenation reaction.

scholarly journals Effect of Preparation Method on ZrO2-Based Catalysts Performance for Isobutanol Synthesis from Syngas

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 752 ◽  
Author(s):  
Yingquan Wu ◽  
Li Tan ◽  
Tao Zhang ◽  
Hongjuan Xie ◽  
Guohui Yang ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Carbon Chain ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Chain Growth ◽  
Impregnation Method ◽  
Surface Areas ◽  
Co Precipitation ◽  
Diffuse Reflectance Infrared

Two types of amorphous ZrO2 (am-ZrO2) catalysts were prepared by different co-precipitation/reflux digestion methods (with ethylenediamine and ammonia as the precipitant respectively). Then, copper and potassium were introduced for modifying ZrO2 via an impregnation method to enhance the catalytic performance. The obtained catalysts were further characterized by means of Brunauer-Emmett-Teller surface areas (BET), X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR), and In situ diffuse reflectance infrared spectroscopy (in situ DRIFTS). CO hydrogenation experiments were performed in a fixed-bed reactor for isobutanol synthesis. Great differences were observed on the distribution of alcohols over the two types of ZrO2 catalysts, which were promoted with the same content of Cu and K. The selectivity of isobutanol on K-CuZrO2 (ammonia as precipitant, A-KCZ) was three times higher than that on K-CuZrO2 (ethylenediamine as precipitant, E-KCZ). The characterization results indicated that the A-KCZ catalyst supplied more active hydroxyls (isolated hydroxyls) for anchoring and dispersing Cu. More importantly, it was found that bicarbonate species were formed, which were ascribed as important C1 species for isobutanol formation on the A-KCZ catalyst surface. These C1 intermediates had relatively stronger adsorption strength than those adsorbed on the E-KCZ catalyst, indicating that the bicarbonate species on the A-KCZ catalyst had a longer residence time for further carbon chain growth. Therefore, the selectivity of isobutanol was greatly enhanced. These findings would extend the horizontal of direct alcohols synthesis from syngas.

Bimetallic Fe-Ni/Zeolite β Catalysts for Hydrogen Generation from Steam Gasification of Palm Kernel Shell

2014 ◽  
Vol 925 ◽  
pp. 313-317
Author(s):  
Anita Ramli ◽  
Siti Eda Eliana Misi ◽  
Mas Fatiha Mohamad ◽  
Suzana Yusup
Keyword(s):  
Hydrogen Generation ◽  
Fixed Bed ◽  
Palm Kernel ◽  
Textural Properties ◽  
Lower Surface ◽  
Steam Gasification ◽  
Impregnation Method ◽  
Palm Kernel Shell ◽  
Calcination Temperatures ◽  
Zeolite Β

In this study, the potential usage of PKS as a direct source for hydrogen production is being explored in the presence of bimetallic Fe-Ni/Zeolite β (BEA) catalyst. The catalyst was prepared by co-impregnation method and calcined at temperatures between 500-700 oC to study the effect of calcination temperatures on the gas compositions from steam gasification of PKS. The textural properties and crystalline phase present were characterized using BET and X-Ray Diffraction. The catalysts were tested in steam gasification of PKS in a fixed-bed microreactor at 700 oC using 0.3 g catalyst and 0.9 g PKS. The steam to PKS ratio was 4:1 (vol) while steam to Ar ratio was 1:6 (vol.). The Fe-Ni/BEA catalysts possess lower surface area, higher pore volume and larger pore diameter as compared to the bare BEACalcination temperature is found to contribute to the crystallization of the prepared catalysts where high crystallization of Fe and Ni was observed in Fe-Ni/BEA (700) catalyst with the formation of NiO and NiFe2O4 phase. Fe-Ni/BEA (700) shows the highest composition of H2 gas produced with 76.32 vol% H2, 18.72 vol% CO2, 4.96 vol% CO and the absence of CH4. This shows that the steam gasification of PKS in the presence of Fe-Ni/BEA (700) has a potential to replace the commercial H2 production via methane reforming process.

Lanthanum Modified Catalyst for Efficient Supply of Hydrogen through Dehydrogenation of Organic Chemical Hydrides

2011 ◽  
Vol 287-290 ◽  
pp. 2110-2115
Author(s):  
Gang Li Zhu ◽  
Tao Chen ◽  
Xue Dong Jiang ◽  
Hai Liang Zhang ◽  
Bo Lun Yang
Keyword(s):  
Energy Dispersive Spectrometer ◽  
Fixed Bed ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Metal Species ◽  
Organic Chemical ◽  
Impregnation Method ◽  
Active Components

Dehydrogenation process of organic chemical hydrides was improved by modifying the catalyst of nickel-activated carbon (Ni/AC) with lanthanum (La). The catalysts were prepared in impregnation method with different amounts of La and Ni. The textural properties and morphology of catalyst were analyzed by nitrogen adsorption and transmission electron microscope equipped with energy dispersive spectrometer respectively. The effects such as metal content and granule size on the dehydrogenation of cyclohexane were investigated in fixed bed reactor. The results show that the metallic active components can be well dispersed on the support, and the elements analysis indicates the metal species tend to assemble on the surface layer rather than being distributed equally in the whole catalyst. The La modified catalyst LaNi/AC exhibited superior catalytic performance to Ni/AC and the conversion was 45% for LaNi/AC catalyst at 673K, while only 34 % for Ni/AC under the same conditions.

scholarly journals Activity Evaluation of CoMo Nanoparticles Supported on Meso-microporous Composites in Dibenzothiophene Hydrodesulphurization

2019 ◽  
Vol 15 (1) ◽  
pp. 112-118
Author(s):  
Nastaran Parsafard ◽  
Mohammad Hasan Peyrovi ◽  
Zahra Mohammadian ◽  
Niloofar Atashi
Keyword(s):  
Activation Energy ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Ft Ir ◽  
Adsorption Desorption

CoMo-supported mesoporous catalysts were synthesized by 50 wt% of HZSM-5 and 50 wt% of FSM-16, KIT-6, and MCM-48. These catalysts were prepared by the wet-impregnation method and pre-sulfided with CS2. The catalytic performance was evaluated for HDS reaction of dibenzothiophene over a temperature range of 250-400 °C in a micro fixed-bed reactor under atmospheric pressure. The supported CoMo bimetallic catalysts were characterized by XRD, XRF, FT-IR, N2 adsorption-desorption, and SEM. The CoMo/KIT-6/HZSM-5 indicate higher activity than other catalysts at 400 °C for dibenzothiophene hydrodesulphurization. Also, the best selectivity to cyclohexylbenzene (CHB) is related to CoMo/FSM-16/HZSM-5. The activation energy was also calculated for all prepared catalysts for the conversions of less than 10%; according to which, the activation energy for CoMo/KIT-6/HZSM-5 is less than other catalysts (~21 kJ/mol) which can be related to the appropriate pore size and high surface area of the support. Copyright © 2020 BCREC Group. All rights reserved 

The relationship between the chemical state of Pd species and the catalytic activity for methane combustion on Pd/CeO2

2018 ◽  
Vol 8 (10) ◽  
pp. 2567-2577 ◽  
Author(s):  
Jian Ma ◽  
Yang Lou ◽  
Yafeng Cai ◽  
Zhenyang Zhao ◽  
Li Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Methane Combustion ◽  
Catalytic Performance ◽  
Chemical State ◽  
Impregnation Method ◽  
The Relationship

Three Pd/CeO2 catalysts are synthesized by reduction-deposition and an impregnation method (IMP) to clarify how the chemical state of Pd influences the catalytic performance for CH4 combustion.

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