- Email: [email protected]
28-O-05-Effect of single-file diffusion on the hydroisomerization of 2,2-dimethylbutane on platinum loaded H-mordenite
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2 8 - 0 - 0 3 Artificial photosynthesis using zeolites N. Castagnola and P.K. Dutta
Department of Chemistry, The Dutta. l @osu. edu
Ohio State University, Columbus, Ohio 43210,
The goal of this study is to assemble a chemical architecture that can split water into hydrogen and oxygen using sunlight. Zeolites provide opportunities for novel spatial arrangement of molecules. The photochemical process begins with electron transfer from sensitizers to acceptor molecules in the zeolite. We find that the short-circuiting back electron transfer process is significantly slower in the zeolite and the intrazeolitic packing of the acceptor molecules also leads to long-lived charge separation and the charge-separated species can be chemically exploited by suitable catalysts. The challenge is to incorporate all these elements of the system into a single architecture and we are examining zeolite membranes for this purpose.
2 8 - 0 - 0 4 - Synthesis of macrocycles using molecular sieve catalysts M. Radha Kishan, N. Srinivas, S.J. Kulkarni*, M. Ramakrishna Prasad, G. Kamalakar and K.V. Raghavan.
Catalysis Group, Indian Institute of Chemical technology, Hyderabad, India For the first time we report the synthesis of macrocycles like calixpyrrole, cyclotriveratrylene (CTV), cyclotetraveratrylene (CTTV), porphyrine etc over molecular sieve as a catalyst. Calixpyrroles are synthesized from pyrrole and a ketone like acetone over MCM-41 under reflux conditions using suitable solvent. In case of MCM-41 cyclic calixpyrroles were obtained. On the other hand due to shape selectivity in case of Y zeolite linear di-, tri- and tetra- polypyrroles were obtained and cyclic tetramers were not observed. The mechanism of the synthesis of calixpyrrole is either by the dimerization of dimer with simultaneous cyclization to cyclic tetramer or cyclization of linear tetramer via recoil phenomenon.
2 8 - 0 - 0 5 - Effect of single-file diffusion on the hydroisomerization of 2,2-dimethylbutane on platinum loaded H-mordenite F.J.M.M. de Gauw, J. van Grondelle and R.A. van Santen
Schuit Institute of Catalysis, Laboratory of Inorganic Chemistry and Catalysis, Eindhoven University of Technology, Eindhoven, The Netherlands - F.J.M.M.de. [email protected] The effect of single-file diffusion limitation on the rate of an irreversible first order catalytic reaction was studied both theoretically and experimentally. A rate equation was derived using a relation between the effective diffusion constant and the concentration of adsorbed molecules under single-file conditions which is valid on the time scale of catalytic reactions. The hydroisomerization of 2,2-dimethylbutane on platinum loaded large crystallites of HMordenite was used as a test reaction to verify the theoretical results.
2 8 - 0 - 0 3 Artificial photosynthesis using zeolites N. Castagnola and P.K. Dutta
Department of Chemistry, The Dutta. l @osu. edu
Ohio State University, Columbus, Ohio 43210,
The goal of this study is to assemble a chemical architecture that can split water into hydrogen and oxygen using sunlight. Zeolites provide opportunities for novel spatial arrangement of molecules. The photochemical process begins with electron transfer from sensitizers to acceptor molecules in the zeolite. We find that the short-circuiting back electron transfer process is significantly slower in the zeolite and the intrazeolitic packing of the acceptor molecules also leads to long-lived charge separation and the charge-separated species can be chemically exploited by suitable catalysts. The challenge is to incorporate all these elements of the system into a single architecture and we are examining zeolite membranes for this purpose.
2 8 - 0 - 0 4 - Synthesis of macrocycles using molecular sieve catalysts M. Radha Kishan, N. Srinivas, S.J. Kulkarni*, M. Ramakrishna Prasad, G. Kamalakar and K.V. Raghavan.
Catalysis Group, Indian Institute of Chemical technology, Hyderabad, India For the first time we report the synthesis of macrocycles like calixpyrrole, cyclotriveratrylene (CTV), cyclotetraveratrylene (CTTV), porphyrine etc over molecular sieve as a catalyst. Calixpyrroles are synthesized from pyrrole and a ketone like acetone over MCM-41 under reflux conditions using suitable solvent. In case of MCM-41 cyclic calixpyrroles were obtained. On the other hand due to shape selectivity in case of Y zeolite linear di-, tri- and tetra- polypyrroles were obtained and cyclic tetramers were not observed. The mechanism of the synthesis of calixpyrrole is either by the dimerization of dimer with simultaneous cyclization to cyclic tetramer or cyclization of linear tetramer via recoil phenomenon.
2 8 - 0 - 0 5 - Effect of single-file diffusion on the hydroisomerization of 2,2-dimethylbutane on platinum loaded H-mordenite F.J.M.M. de Gauw, J. van Grondelle and R.A. van Santen
Schuit Institute of Catalysis, Laboratory of Inorganic Chemistry and Catalysis, Eindhoven University of Technology, Eindhoven, The Netherlands - F.J.M.M.de. [email protected] The effect of single-file diffusion limitation on the rate of an irreversible first order catalytic reaction was studied both theoretically and experimentally. A rate equation was derived using a relation between the effective diffusion constant and the concentration of adsorbed molecules under single-file conditions which is valid on the time scale of catalytic reactions. The hydroisomerization of 2,2-dimethylbutane on platinum loaded large crystallites of HMordenite was used as a test reaction to verify the theoretical results.