An ESR study of titanium-silicalite in presence of H2O2.
The interaction of H2O2 with TS-1 has been investigated by the ESR technique. A well manufactured TS-1 has been considered, where the presence of extra-structural titanium can be excluded. The two main signals observed are attributed to oxygen radical species co-ordinated on structural titanium sites, and the relevant effect of water presence in the paramagnetic complex is discussed. A comparison is performed with O2-/Ti species in TS-1 obtained by reduction/re-oxidation procedures of Ti(IV). Moreover, some possible structural configurations of the paramagnetic sites are proposed, for two of which ab initio calculation yield g(z)-values quite close to the experimental ones.
Bonoldi
L
L
Enichem Norara, Italy. lucia.bonoldi@enichem.it
Busetto
C
C
Congiu
A
A
Marra
G
G
Ranghino
G
G
Salvalaggio
M
M
Spanò
G
G
Giamello
E
E
D000838:Anions; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008956:Models, Chemical; D010100:Oxygen; D017640:Silicates / Q000032:analysis / Q000737:chemistry*; D013696:Temperature; D014025:Titanium / Q000032:analysis / Q000737:chemistry*; D014466:Ultraviolet Rays
D000838:Anions; D017640:Silicates; C103828:titanium silicide; D006861:Hydrogen Peroxide; D014025:Titanium; D010100:Oxygen