Synthesis and properties of TiO2-P2O5 and SiO2-TiO2-P2O5 porous hybrids obtained by templating in highly concentrated emulsions
| Autor: | Lourdes A. Pérez-Carrillo, Yolanda Castro, Mario Aparicio, Susana Vílchez, J.M.D. Tascón, Adrian Duran, Jadra Mosa, Jordi Esquena |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Process Chemistry and Technology Proton exchange membrane fuel cell Nanotechnology Sorption 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Dielectric spectroscopy chemistry.chemical_compound Chemical engineering chemistry Phase (matter) Materials Chemistry Ceramics and Composites Polystyrene 0210 nano-technology Porosity Mesoporous material Hybrid material |
| Zdroj: | Ceramics International. 42:18965-18973 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2016.09.050 |
| Popis: | Hybrid inorganic oxides which have simultaneously meso- and macro-porous texture leading to high surface area and high pore volume were prepared by templating in polystyrene monoliths in highly concentrated emulsions. The synthesis was carried out by a two-step method. In the first step, macroporous polystyrene monoliths were prepared using highly concentrated Water-in-Oil (W/O) emulsions as templates, by polymerizing in the external phase of the emulsions. In the second step, the polystyrene monoliths were impregnated with TiO 2 -P 2 O 5 or SiO 2 -TiO 2 -P 2 O 5 sol-gel precursors. Using sol-gel condensation reactions, hybrid inorganic oxide materials were successfully obtained with complex porous structures. The porosity was characterized by electron microscopy (SEM and TEM), and nitrogen sorption. Nitrogen isotherms confirmed that binary TiO 2 -P 2 O 5 hybrid materials were mainly macroporous while ternary hybrid SiO 2 -TiO 2 -P 2 O 5 had all sorts of pores; micropores, mesopores and macropores, with surface area around 300 m 2 /g. Preliminary electrochemical evaluation of these materials has been performed, aiming at possible applications as elements in Proton Exchange Membrane Fuel Cells (PEMFC). Results of conductivity, obtained by Electrochemical Impedance Spectroscopy (EIS) have shown excellent proton conductivity, particularly at low temperatures. Most likely, this is a consequence of high water retention capacity, in small interconnected pores, and acidity provided by P–OH groups on pore surface. |
| Databáze: | OpenAIRE |
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