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
It is shown that the potassium polytitanate powder (PPT) synthesized at 500 °C via the treatment of powdered TiO<sub>2</sub> (rutile) in molten mixtures of KOH and KNO<sub>3</sub> is a cheap and effective catalyst of H<sub>2</sub>O<sub>2</sub> chemical...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-06-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/28/13/4945 |
| _version_ | 1797591182175371264 |
|---|---|
| author | Alexander Gorokhovsky Natalia Morozova Gleb Yurkov Olga Grapenko Alexander Kozinkin Alexei Kozakov Anatoliy Nikolskiy Elena Tretyachenko Andrey Semenov Vitaliy Solodilov |
| author_facet | Alexander Gorokhovsky Natalia Morozova Gleb Yurkov Olga Grapenko Alexander Kozinkin Alexei Kozakov Anatoliy Nikolskiy Elena Tretyachenko Andrey Semenov Vitaliy Solodilov |
| author_sort | Alexander Gorokhovsky |
| collection | DOAJ |
| description | It is shown that the potassium polytitanate powder (PPT) synthesized at 500 °C via the treatment of powdered TiO<sub>2</sub> (rutile) in molten mixtures of KOH and KNO<sub>3</sub> is a cheap and effective catalyst of H<sub>2</sub>O<sub>2</sub> chemical decomposition in aqueous solutions. At the same time, the PPT catalytic activity strongly depends on the [TiO<sub>2</sub>]:[KOH]:[KNO<sub>3</sub>] weight ratio in the mixture used for the synthesis, increasing with [KNO<sub>3</sub>] in the order of PPT (30:30:40) < PPT (30:50:20) < PPT (30:70:0). The obtained results are explained by increased [Ti<sup>3+</sup>] 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-H<sub>2</sub>O<sub>2</sub>-H<sub>2</sub>O 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 Ti<sup>4+</sup>-O(H)-Ti<sup>4+</sup> groups, formed from the Ti<sup>3+</sup>-O(H<sub>3</sub>O<sup>+</sup>)-Ti<sup>4+</sup> clusters and further transformed into Ti-O-O-H catalytic centers. Some possible applications of the PPT-H<sub>2</sub>O<sub>2</sub>-H<sub>2</sub>O catalytic system, including the oxidation processes of green chemistry and photo-catalysis, are discussed. |
| first_indexed | 2024-03-11T01:33:53Z |
| format | Article |
| id | doaj.art-1a68c930001e4eb1a905303ee6073768 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-11T01:33:53Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-1a68c930001e4eb1a905303ee60737682023-11-18T17:05:49ZengMDPI AGMolecules1420-30492023-06-012813494510.3390/molecules28134945Catalytic 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 SynthesisAlexander Gorokhovsky0Natalia Morozova1Gleb Yurkov2Olga Grapenko3Alexander Kozinkin4Alexei Kozakov5Anatoliy Nikolskiy6Elena Tretyachenko7Andrey Semenov8Vitaliy Solodilov9Department of Materials Chemistry and Technology, Yuri Gagarin State Technical University of Saratov, Polytekhnicheskaya 77, Saratov 410054, RussiaDepartment of Materials Chemistry and Technology, Yuri Gagarin State Technical University of Saratov, Polytekhnicheskaya 77, Saratov 410054, RussiaN.N. Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, Kosygina 4, Moscow 119991, RussiaResearch Institute of Physics, Southern Federal University, pr. Stachki 194, Rostov-on-Don 344090, RussiaResearch Institute of Physics, Southern Federal University, pr. Stachki 194, Rostov-on-Don 344090, RussiaResearch Institute of Physics, Southern Federal University, pr. Stachki 194, Rostov-on-Don 344090, RussiaResearch Institute of Physics, Southern Federal University, pr. Stachki 194, Rostov-on-Don 344090, RussiaDepartment of Materials Chemistry and Technology, Yuri Gagarin State Technical University of Saratov, Polytekhnicheskaya 77, Saratov 410054, RussiaN.N. Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, Kosygina 4, Moscow 119991, RussiaN.N. Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, Kosygina 4, Moscow 119991, RussiaIt is shown that the potassium polytitanate powder (PPT) synthesized at 500 °C via the treatment of powdered TiO<sub>2</sub> (rutile) in molten mixtures of KOH and KNO<sub>3</sub> is a cheap and effective catalyst of H<sub>2</sub>O<sub>2</sub> chemical decomposition in aqueous solutions. At the same time, the PPT catalytic activity strongly depends on the [TiO<sub>2</sub>]:[KOH]:[KNO<sub>3</sub>] weight ratio in the mixture used for the synthesis, increasing with [KNO<sub>3</sub>] in the order of PPT (30:30:40) < PPT (30:50:20) < PPT (30:70:0). The obtained results are explained by increased [Ti<sup>3+</sup>] 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-H<sub>2</sub>O<sub>2</sub>-H<sub>2</sub>O 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 Ti<sup>4+</sup>-O(H)-Ti<sup>4+</sup> groups, formed from the Ti<sup>3+</sup>-O(H<sub>3</sub>O<sup>+</sup>)-Ti<sup>4+</sup> clusters and further transformed into Ti-O-O-H catalytic centers. Some possible applications of the PPT-H<sub>2</sub>O<sub>2</sub>-H<sub>2</sub>O catalytic system, including the oxidation processes of green chemistry and photo-catalysis, are discussed.https://www.mdpi.com/1420-3049/28/13/4945layered titanatesstructural featuresH<sub>2</sub>O<sub>2</sub> decompositioncatalysiskinetics and mechanism |
| spellingShingle | Alexander Gorokhovsky Natalia Morozova Gleb Yurkov Olga Grapenko Alexander Kozinkin Alexei Kozakov Anatoliy Nikolskiy Elena Tretyachenko Andrey Semenov Vitaliy Solodilov 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 Molecules layered titanates structural features H<sub>2</sub>O<sub>2</sub> decomposition catalysis kinetics and mechanism |
| title | 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 |
| title_full | 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 |
| title_fullStr | 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 |
| title_full_unstemmed | 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 |
| title_short | 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 |
| title_sort | 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 |
| topic | layered titanates structural features H<sub>2</sub>O<sub>2</sub> decomposition catalysis kinetics and mechanism |
| url | https://www.mdpi.com/1420-3049/28/13/4945 |
| work_keys_str_mv | AT alexandergorokhovsky catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT nataliamorozova catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT glebyurkov catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT olgagrapenko catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT alexanderkozinkin catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT alexeikozakov catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT anatoliynikolskiy catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT elenatretyachenko catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT andreysemenov catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis AT vitaliysolodilov catalyticdecompositionofhsub2subosub2subintheaqueousdispersionsofthepotassiumpolytitanatesproducedindifferentconditionsofmoltensaltsynthesis |