Catalytic Decomposition of H<sub>2</sub>O<sub>2</sub> in the Aqueous Dispersions of the Potassium Polytitanates Produced in Different Conditions of Molten Salt Synthesis
Alexander Gorokhovsky,
Natalia Morozova,
Gleb Yurkov,
Olga Grapenko,
Alexander Kozinkin,
Alexei Kozakov,
Anatoliy Nikolskiy,
Elena Tretyachenko,
Andrey Semenov,
Vitaliy Solodilov
Affiliations
Alexander Gorokhovsky
Department of Materials Chemistry and Technology, Yuri Gagarin State Technical University of Saratov, Polytekhnicheskaya 77, Saratov 410054, Russia
Natalia Morozova
Department of Materials Chemistry and Technology, Yuri Gagarin State Technical University of Saratov, Polytekhnicheskaya 77, Saratov 410054, Russia
Gleb Yurkov
N.N. Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, Kosygina 4, Moscow 119991, Russia
Olga Grapenko
Research Institute of Physics, Southern Federal University, pr. Stachki 194, Rostov-on-Don 344090, Russia
Alexander Kozinkin
Research Institute of Physics, Southern Federal University, pr. Stachki 194, Rostov-on-Don 344090, Russia
Alexei Kozakov
Research Institute of Physics, Southern Federal University, pr. Stachki 194, Rostov-on-Don 344090, Russia
Anatoliy Nikolskiy
Research Institute of Physics, Southern Federal University, pr. Stachki 194, Rostov-on-Don 344090, Russia
Elena Tretyachenko
Department of Materials Chemistry and Technology, Yuri Gagarin State Technical University of Saratov, Polytekhnicheskaya 77, Saratov 410054, Russia
Andrey Semenov
N.N. Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, Kosygina 4, Moscow 119991, Russia
Vitaliy Solodilov
N.N. Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, Kosygina 4, Moscow 119991, Russia
It is shown that the potassium polytitanate powder (PPT) synthesized at 500 °C via the treatment of powdered TiO2 (rutile) in molten mixtures of KOH and KNO3 is a cheap and effective catalyst of H2O2 chemical decomposition in aqueous solutions. At the same time, the PPT catalytic activity strongly depends on the [TiO2]:[KOH]:[KNO3] weight ratio in the mixture used for the synthesis, increasing with [KNO3] in the order of PPT (30:30:40) 3+] in the PPT structure (XPS data), which is grown in this order from 0 to 4.0 and 21.9 at.%, respectively, due to the reduced oxidation activity of the melt used for PPT synthesis. The mechanism of the autocatalytic process taking place in the PPT-H2O2-H2O system is analyzed. Taking into account the data of FT-IR spectroscopy, it is assumed that the increased catalytic activity of the investigated materials is related to the increased surface concentration of the Ti4+-O(H)-Ti4+ groups, formed from the Ti3+-O(H3O+)-Ti4+ clusters and further transformed into Ti-O-O-H catalytic centers. Some possible applications of the PPT-H2O2-H2O catalytic system, including the oxidation processes of green chemistry and photo-catalysis, are discussed.
