David Raju Burri

Combined Promotional Effect of CO2 and Ni on Co/Mn/Br Catalyst in the Liquid-Phase Oxidation of p-Xylene

The promotional effects of CO2 and Ni were studied on Co/Mn/Br catalyst in the liquid-phase oxidation of p-xylene to terephthalic acid using molecular oxygen as an oxidant and acetic acid as a solvent individually as well as in combination. The enhanced activity of Co/Mn/Br catalyst was observed on both CO2 and Ni promoters independently and also in combination. The activity enhancement in the combination of CO2 and Ni promoters on this catalyst is found to be remarkable.

Mechanistic Aspects of Ethylbenzene Dehydrogenation with CO2 over K2O/B2O3 -TiO2 - ZrO2 Bi-Functional Catalysts

TiO 2 -ZrO 2 bi-functional catalysts were prepared by co-precipitation method using aqueous NH 3 solution as a hydrolyzing agent. Either K 2 O promoter or B 2 O 3 promoter has been deposited 60% TiO 2 - ZrO 2 by wet-impregnation techniques. The catalytic activity of both K 2 O promoted and B 2 O 3 promoted TiO 2 -ZrO 2 acid base bi-functional catalysts has been studied for the oxidative dehydrogenation of ethylbenzene in the presence of CO 2 . The higher conversion of ethylbenzene and higher selectivity of styrene has been obtained on the K 2 O promoted TiO 2 -ZrO 2 catalysts. On the other hand, B 2 O 3 promoted TiO 2 - ZrO 2 catalysts exhibited lower catalytic activity than those of K 2 O promoted TiO 2 - ZrO 2 catalysts. In the mechanistic point of view both K 2 O promoted TiO 2 -ZrO 2 catalysts and B 2 O 3 promoted TiO 2 - ZrO 2 catalysts following the different pathways. This synergistic promotional effects of K 2 O and CO 2 enhanced the selectivity of styrene (98 - 99%) by sustaining the higher conversions of ethylbenzene (60 -65%).

Microwave Synthesis and Characterization of Stacked AlTS-1

Nano-stacked aluminum titanium silicalite-1(NS-AlTS-1) zeolite with MFI structure was prepared by direct synthesis using a microwave technique and also prepared the conventional aluminum titanium silicalite-1(AlTS-1) by conventional hydrothermal method for comparison. The morphological aspects of these materials were investigated with the help of SEM. The zeolite framework Al location was confirmed by 27Al MAS NMR. The existence of Ti species in the zeolite framework and its co-ordination environment was investigated by UV-Vis spectroscopy. The uni-model distribution of weak acidic sites was estimated by the well established NH3-TPD technique.

Microwave synthesis of SBA-15 mesoporous silica material for beneficial effect on the hydrothermal stability

Hydrothermally robust mesoporous SBA-15 silica material was synthesized for the first time using microwave with out adding any other chemical ingredients. For the sake of stability comparison, mesoporous SBA-15 material was also prepared by conventional hydrothermal technique. The stability of the material was tested by boiling water method and 29 Si-NMR Q 4 /Q 3 ratios. It was observed that SBA-15 synthesized under microwave conditions exhibited higher stability than that of hydrothermally synthesized SBA-15.