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Dexterous template-free synthesis of ferrisilicate with MFI morphology using rice husk ash
Bhagiyalakshmi, Margandan,Anuradha, Ramani,Palanichamy, Muthiahpillai,Jang, Hyun Tae Elsevier 2010 Journal of non-crystalline solids Vol.356 No.23
<P><B>Abstract</B></P><P>Sodium silicate, the supernatant solution extracted from rice husk ash was used as silica source in hydrothermal synthesis of Fe ZSM-5 zeolites by an organic-free method. Characterization techniques such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), BET, X-Ray Fluorescence (XRF), Diffuse Reflectance Spectroscopy — Ultra Violet (DRS-UV) and Temperature-Programmed Desorption-ammonia (NH<SUB>3</SUB>-TPD) unambiguously confirm the formation of Fe ZSM-5. Phosphoric acid used in the synthesis, forms an oxo-anion complex with iron and this complex acts as surface directing agent in the formation of Fe ZSM-5 zeolites. Characterization results prove that rice husk ash can successfully be recycled as ferrisilicates with MFI morphology even in the absence of template.</P>
Transesterification of Jatropha Oil over Ceria-Impregnated ZSM-5 for the Production of Bio-Diesel
Bhagiyalakshmi, Margandan,Vinoba, Mari,Grace, Andrews Nirmala Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.10
In this study transesterification of Triglycerides (TG) from Jatropha curcas oil (JCO) with methanol for production of biodiesel was investigated over cerium impregnated ZSM-5 catalysts. NaZSM-5 was synthesized in an alkaline medium and impregnated with cerium oxide by wet method using cerium nitrate as a source for cerium. They were characterized by X-ray diffraction (XRD), Thermogravimeteric analysis (TGA), $CO_2$-temperature programmed desorption, and $N_2$ adsorption/desorption analysis. XRD analysis showed decrease in intensity of the patterns with the increase in the ceria loading but crystallization of ceria to larger size is an evident for 10 and 15% loading. The optimal yield of transesterification process was found to be 90% under the following conditions: oil to methanol molar ratio: 1:12; temperature: $60^{\circ}C$; time: 1 h; catalyst: 5 wt %. Here the yield of fatty acid methyl ester (FAME) was calculated through $^1H$ NMR analysis. The investigation on catalyst loading, temperature, time and reusability illustrated that these ceria impregnated NaZSM-5's were found to be selective, recyclable and could yield biodiesel at low temperature with low methanol to oil ratio due to the presence of both Lewis and Bronsted basicity. Hence, from the above study it is concluded that ceria impregnated ZSM-5 could be recognized as a potential catalysts for biodiesel production in industrial processes.
Bhagiyalakshmi, Margandan,Anuradha, Ramani,Park, Sang-Do,Park, Tae-Sung,Cha, Wang-Seog,Jang, Hyun-Tae Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.1
Monometallic, bimetallic and trimetallic particles consisting of different weight compositions of Pt-Pd-Rh over pure alumina wash coats have been synthesized and their catalytic performance on methane conversion was studied from 150 to $600^{\circ}C$. Different catalyst formulations with variable Pt, Pd and Rh contents for bimetallic and trimetallic systems were tried and $Pt_{(1.5)}Rh_{(0.3)}/Al_2O_3$ and $Pt_{(1.0)}Pd_{(1.0)}Rh_{(0.3)}/Al_2O_3$ shows low $T_{50}$ and $T_{90}$ temperatures. Bimetallic and trimetallic particle synergism acts as three way catalysts and therefore, all the catalysts show 100% methane conversion. The effect of supports such as $ZrO_2$ and $TiO_2$ on methane combustion was investigated; from $T_{50}$ and $T_{90}$ results both $Al_2O_3$ and $ZrO_2$ are suitable supports for low temperature methane combustion.
Bhagiyalakshmi, M.,Yun, L.J.,Anuradha, R.,Jang, H.T. Elsevier Scientific Pub. Co 2010 Journal of hazardous materials Vol.175 No.1
Mesoporous MCM-41, MCM-48 and SBA-15 were synthesized using Rice husk ash (RHA) as the silica source and their defective Si-OH sites were functionalized by 3-cholropropyltrimethoxysilane (CPTMS) which was subsequently grafted with amine compounds, Tris(2-aminoethyl)amine (TREN) and Tetraethylenepentamine (TEPA). X-ray powder diffraction (XRD) and BET results of the parent mesoporous silica suggested their closeness of structural properties to those obtained from conventional silica sources. CO<SUB>2</SUB> adsorption of branched amine TREN and straight chain amine TEPA at 25, 50 and 75<SUP>o</SUP>C was obtained by Thermogravimetric Analyser (TGA) at atmospheric pressure. TREN grafted mesoporous silica showed 7% of CO<SUB>2</SUB> adsorption while TEPA grafted mesoporous silicas showed less CO<SUB>2</SUB> adsorption, which is due to the presence of isolated amine groups in TREN. TREN grafted mesoporous silicas were also observed to be selective towards CO<SUB>2</SUB>, thermally stable and recyclable. The order of CO<SUB>2</SUB> adsorption with respect to amount of amine grafting was observed to be MCM-48/TREN>MCM-41/TREN>SBA-15/TREN.
Bhagiyalakshmi, M.,Hemalatha, P.,Ganesh, M.,Peng, M.M.,Jang, H.T. Korean Society of Industrial and Engineering Chemi 2011 Journal of industrial and engineering chemistry Vol.17 No.3
Copper-encapsulated heteropolyacid-impregnated mesoporous MCM-48 (Cu-HPA-MCM-48) with copper in a reduced state was synthesized, and the CO<SUB>2</SUB> adsorption capacity was monitored. The synthesized material was characterized by XRD, N<SUB>2</SUB> adsorption-desorption, FT-IR, DSC, CO<SUB>2</SUB>-TPD and XPS. The low angle X-ray diffraction pattern of the Cu-HPA-MCM-48 demonstrates the encapsulation of copper inside the pore by the disappearance of higher-order peaks. This result is further supported by the presence of Cu<SUB>2p</SUB><SUP>3</SUP> and W<SUB>4f</SUB> peaks in XPS. The CO<SUB>2</SUB> adsorption capacity of Cu-HPA-MCM-48 was 70mg/g at 25<SUP>o</SUP>C. The energy of desorption and the heat of the reaction (ΔHr) were 21.2kJ/mol and 490Btu/lb, respectively, as determined by CO<SUB>2</SUB>-TPD and DSC. As the ΔHr value of Cu-HPA-MCM-48 approaches the CO<SUB>2</SUB> benchmark value (580Btu/lb), the catalyst exhibited improved CO<SUB>2</SUB> capturing capacity.
Margandan Bhagiyalakshmi,장현태,PUSHPARAJHEMALATHA,Mani Ganesh,Mei Mei Peng 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.3
Copper-encapsulated heteropolyacid-impregnated mesoporous MCM-48 (Cu-HPA-MCM-48) with copper in a reduced state was synthesized, and the CO_2 adsorption capacity was monitored. The synthesized material was characterized by XRD, N_2 adsorption–desorption, FT-IR, DSC, CO_2-TPD and XPS. The low angle X-ray diffraction pattern of the Cu-HPA-MCM-48 demonstrates the encapsulation of copper inside the pore by the disappearance of higher-order peaks. This result is further supported by the presence of Cu_(2p)^3 andW4f peaks in XPS. The CO_2 adsorption capacity of Cu-HPA-MCM-48was 70 mg/g at 25℃. The energy of desorption and the heat of the reaction (DHr) were 21.2 kJ/mol and 490 Btu/lb,respectively, as determined by CO_2-TPD and DSC. As the DHr value of Cu-HPA-MCM-48 approaches the CO_2 benchmark value (580 Btu/lb), the catalyst exhibited improved CO_2 capturing capacity.
Markandan Bhagiyalakshmi,Ramani Anuradha,Sang Do Park,Tae Sung Park,차왕석,장현태 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.1
Monometallic, bimetallic and trimetallic particles consisting of different weight compositions of Pt-Pd-Rh over pure alumina wash coats have been synthesized and their catalytic performance on methane conversion was studied from 150 to 600 oC. Different catalyst formulations with variable Pt, Pd and Rh contents for bimetallic and trimetallic systems were tried and Pt(1.5)Rh(0.3)/Al2O3 and Pt(1.0)Pd(1.0)Rh(0.3)/Al2O3 shows low T50 and T90 temperatures. Bimetallic and trimetallic particle synergism acts as three way catalysts and therefore, all the catalysts show 100% methane conversion. The effect of supports such as ZrO2 and TiO2 on methane combustion was investigated; from T50 and T90 results both Al2O3 and ZrO2 are suitable supports for low temperature methane combustion.
Transesterification of Jatropha Oil over Ceria-Impregnated ZSM-5 for the Production of Bio-Diesel
Margandan Bhagiyalakshmi,Mari Vinoba,Andrews Nirmala Grace 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.10
In this study transesterification of Triglycerides (TG) from Jatropha curcas oil (JCO) with methanol for production of biodiesel was investigated over cerium impregnated ZSM-5 catalysts. NaZSM-5 was synthesized in an alkaline medium and impregnated with cerium oxide by wet method using cerium nitrate as a source for cerium. They were characterized by X-ray diffraction (XRD), Thermogravimeteric analysis (TGA), CO2- temperature programmed desorption, and N2 adsorption/desorption analysis. XRD analysis showed decrease in intensity of the patterns with the increase in the ceria loading but crystallization of ceria to larger size is an evident for 10 and 15% loading. The optimal yield of transesterification process was found to be 90% under the following conditions: oil to methanol molar ratio: 1:12; temperature: 60 °C; time: 1 h; catalyst: 5 wt %. Here the yield of fatty acid methyl ester (FAME) was calculated through 1H NMR analysis. The investigation on catalyst loading, temperature, time and reusability illustrated that these ceria impregnated NaZSM-5’s were found to be selective, recyclable and could yield biodiesel at low temperature with low methanol to oil ratio due to the presence of both Lewis and Bronsted basicity. Hence, from the above study it is concluded that ceria impregnated ZSM-5 could be recognized as a potential catalysts for biodiesel production in industrial processes.
Role of ceria in CO2 adsorption on NaZSM-5 synthesized using rice husk ash
PUSHPARAJHEMALATHA,Margandan Bhagiyalakshmi,Mani Ganesh,Muthaihpillai Palanichamy,Velayutham Murugesan,장현태 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1
Ceria (3, 5, 7, 11, 19 wt%) impregnated NaZSM-5 was synthesized and studied for adsorption of CO2. They were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive Xray analysis (EDS), CO2-temperature programmed desorption (CO2-TPD) and Brunauer–Emmett–Teller (BET) techniques. The heat of the reaction (DHr) derived from differential scanning calorimetry (DSC)analysis was 490 Btu/lb. XRD analysis showed a decrease in the intensity of patterns with the increase in the ceria loading but crystallization of ceria to larger size was clearly evident for 11 and 19% loading. The surface area decreased for 3 and 5% loading, but increased for 7, 11 and 19% loading illustrating difference in dispersion. The maximum adsorption capacity of CeO2(5%)/NaZSM-5 was 130 mg/g of sorbent. Extraction of silica from the agricultural waste, rice husk, and its use in the zeolite synthesis was an advantage in this study. Hence, from the study it was concluded that ceria impregnated NaZSM-5 could be treated as a novel material for CO2 adsorption, as they were regenerable and recyclable. This study can also be applied to all other zeolites.