Voltammetric characterization of structural titanium species in zeotypes

Ti4+ ions structurally contained in titanium silicalite (TS-1) and ETS-10 samples, two nanoporous materials, have been studied by means of voltammetric measurements. Both structurally tetrahedral and octahedral Ti4+ ions show electrochemical response. In particular, by using acid solutions, it was possible to distinguish, in TS-1, between signals coming from different titanium species. Finally, it has been proven that the use of acid solutions allows us to discriminate between Ti4+ ions in TS-1 and in ETS-10 since only the former is able to coordinate water molecules, the reduction of which can be monitored by the presence of a peak at -600 mV/SSE.