A facile one-pot hydrothermal synthesis as an efficient method to modulate the potassium content of cryptomelane and its effects on the redox and catalytic properties
| Autor: | José M. Rodríguez-Izquierdo, Miguel A. Cauqui, Oihane Sanz, Xiaowei Chen, Huiyan Pan, Juan José Delgado |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Aqueous solution
Reducing agent Chemistry Potassium chemistry.chemical_element 02 engineering and technology General Medicine engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Redox 0104 chemical sciences Catalysis Potassium permanganate chemistry.chemical_compound Chemical engineering engineering Cryptomelane Hydrothermal synthesis 0210 nano-technology |
| Zdroj: | Chinese Journal of Catalysis. 40:940-952 |
| ISSN: | 1872-2067 |
| Popis: | Cryptomelane has been widely applied as catalyst in oxidation reactions due to its excellent redox properties and low cost. Here, a novel one-pot hydrothermal synthesis using a potassium permanganate aqueous solution as precursor and ethanol as reducing agent has successfully been developed to obtain cryptomelane nano-oxides. This synthetic route makes it possible to control the amount of potassium incorporated into the structure of the cryptomelane by selecting the appropriate synthesis temperature and ethanol initial concentration. Taking advantage of this approach, the effect of potassium concentration on the structural stability and reducibility of the cryptomelane, which are poorly discussed in the literature, has been studied. We have observed that samples with low content of potassium (∼11%) show high conversions of CO to CO2 especially at low temperatures. The lower activity of the samples with high K contents (∼16%) can be ascribed to the beneficial effect of K on the structural stability of cryptomelane in detriment of labile oxygen on cryptomelane surface. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect