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Burri, David Raju,Choi, Kwang-Min,Han, Sang-Cheol,Burri, Abhishek,Park, Sang-Eon Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.1
In the dehydrogenation of ethylbenzene to styrene, CO2 could play a role as an oxidant to increase conversion of ethylbenzene and stability as well over TiO2-ZrO2 mixed oxide catalysts. TiO2-ZrO2 catalysts were prepared by co-precipitation method and were characterized by BET surface area, bulk density, X-ray diffraction, temperature programmed desorption of NH3 and CO2. These catalysts were found to be X-ray amorphous with enhanced surface areas and acid-base properties both in number and strength when compared to the respective oxides (TiO2 and CO2). These catalysts were found to be highly active (> 50% conversion), selective (> 98%) and catalytically stable (10 h of time-on-stream) at 600 oC for the dehydrogenation of ethylbenzene to styrene. However, in the nitrogen stream, both activity and stability were rather lower than those in the stream with CO2. The TiO2-ZrO2 catalysts were catalytically superior to the simple oxide catalysts such as TiO2 and ZrO2. The synergistic effect of CO2 has clearly been observed in directing the product selectivity and prolonging catalytic activity.
Dehydrogenation of Ethylbenzene to Styrene with CO2 over TiO2-ZrO2 Bifunctional Catalyst
David Raju Burri,Kwang-Min Choi,Sang-Cheol Han,Abhishek Burri,Sang-Eon Park* 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.1
In the dehydrogenation of ethylbenzene to styrene, CO2 could play a role as an oxidant to increase conversion of ethylbenzene and stability as well over TiO2-ZrO2 mixed oxide catalysts. TiO2-ZrO2 catalysts were prepared by co-precipitation method and were characterized by BET surface area, bulk density, X-ray diffraction, temperature programmed desorption of NH3 and CO2. These catalysts were found to be X-ray amorphous with enhanced surface areas and acid-base properties both in number and strength when compared to the respective oxides (TiO2 and CO2). These catalysts were found to be highly active (>50% conversion), selective (>98%) and catalytically stable (10 h of time-on-stream) at 600 oC for the dehydrogenation of ethylbenzene to styrene. However, in the nitrogen stream, both activity and stability were rather lower than those in the stream with CO2. The TiO2-ZrO2 catalysts were catalytically superior to the simple oxide catalysts such as TiO2 and ZrO2. The synergistic effect of CO2 has clearly been observed in directing the product selectivity and prolonging catalytic activity.
Burri, Abhishek,Jiang, Nanzhe,Yahyaoui, Khalid,Park, Sang-Eon Elsevier 2015 Applied Catalysis A Vol.495 No.-
<P><B>Abstract</B></P> <P>Oxidative dehydrogenation of ethylbenzene (EB) to styrene monomer (SM) over alkali metal (Na, K) doped TiO<SUB>2</SUB>-ZrO<SUB>2</SUB> (TZ) has been studied. The EB and CO<SUB>2</SUB> conversions observed over alkali doped TZ are higher than that of non-doped TZ. The enhanced CO<SUB>2</SUB> conversion compared with non-doped counterparts is attributed to improved basicity, formation of TiZrO<SUB>4</SUB> phase with increased CO<SUB>2</SUB> affinity and insertion of K or Na into the lattice which affects the binding energy of “O” in turn providing more labile oxygen species. Alkali doping also effected in fine tuning the surface acid base properties. Moreover, these K and Na doped binary metal oxides system showed high surface area of 256m<SUP>2</SUP>/g and 199m<SUP>2</SUP>/g respectively. There was a 10-fold increase in the CO<SUB>2</SUB> conversions in case of the doped TZ compared to non-doped TZ increasing the stability of the catalyst by decreasing coking on the surface of the catalyst in spite of the high conversions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Acid–base bifunctional TiO<SUB>2</SUB>-ZrO<SUB>2</SUB>. </LI> <LI> Doping of alkali metal into TiO<SUB>2</SUB>-ZrO<SUB>2</SUB>. </LI> <LI> Increasing CO<SUB>2</SUB> conversion by increasing surface basicity. </LI> <LI> Improved surface oxygen species. </LI> <LI> Highly stable alkali doped TiO<SUB>2</SUB>-ZrO<SUB>2</SUB> for oxidehydrogenation of ethylbenzene to styrene with CO<SUB>2</SUB>. </LI> </UL> </P>
( Abhishek Burri ),모용환,박상언 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0
Oxidative dehydrogenation of propane was studied intensively over Cr and Vanadium based catalysts under CO2. In the dehydrogenation of propane with CO2, different oxide materials were investigated as catalysts. Cr promoted catalysts with different loadings of Cr has been synthesized using MW and applied in the oxidative dehydrogenation of propane to propylene using CO2 as soft oxidant. Loading of chromium ranged from 1 to 5 wt % showing very high surface area. The present catalysts showed high activity (20%) and stability even after 8 hours of reaction. The ratio of Cr6+ and Cr3+ are the main reasons for the high activity. Alkali and alkaline earth metal are proved to activate CO2. The basic nature of these promoters activate COx and enhance the stability of the catalysts. The present study is based on the promotional effect of alkali and alkaline earth metals. Alkali promotion has improved the CO2 conversion by altering the acid base properties of the catalyst and stabilizing the redox nature.
Mesoporous carbon supported MgO for CO2 capture and separation of CO2/N2
Harshitha Burri,Rumana Anjum,Ramesh Babu Gurram,Harisekhar Mitta,Suresh Mutyala,Madhavi Jonnalagadda 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.9
Mesoporous carbon derived from pongamia pinnata fruit hulls was used as support to incorporate magnesium oxide for the study of CO2 adsorption and separation of CO2/N2. All synthesized adsorbents were characterized by PXRD, N2 adsorption-desorption isotherms, Raman and SEM with EDX techniques. Characterization results revealed the existence of magnesium oxide on mesoporous carbon. CO2 adsorption on MgO incorporated mesoporous carbon was higher than bulk mesoporous carbon, due to the electrostatic interaction between magnesium oxide and CO2. High CO2 adsorption capacity 1.68mmol/g was obtained for 10 wt% MgO incorporated mesoporous carbon at 298 K, 1 bar compared to remaining loadings, because of the high content of MgO. However, the N2 adsorption capacity decreased with the increase of MgO content due to a decrease in surface area and no interaction of the N2 molecule with the adsorbent. The selectivity of CO2/N2 was higher on 10 wt% MgO incorporated mesoporous carbon and the value was 40. The heat of CO2 adsorption was 36KJ/mol at low coverage of CO2, and CO2 adsorption capacity was constant in each adsorption cycle over the same adsorbent.