Hybrid membranes containing titanium dioxide doped with fluorine

Abstract

Hybrid membranes based on crystalline titanium dioxide containing fluorine atoms within the crystalline lattice comprising atoms of titanium and oxygen are described; these hybrid membranes are particularly suitable for the production of fuel cells and electrolysers. A process for producing the aforesaid hybrid membranes is also described.

Claims

1. An ion conducting inorganic/organic hybrid membrane comprising fluorine-doped crystalline titanium dioxide particles obtained by a method of preparing ion conducting inorganic/organic hybrid membranes, comprising using fluorine-doped crystalline titanium dioxide particles to prepare ion conducting inorganic/organic hybrid membranes, wherein the fluorine-doped crystalline titanium dioxide particles is in the form of crystalline titanium dioxide particles having an average particle size of between 10 and 500 nm and having fluorine content of between 0.5 and 5% by weight.

2. A fuel cell containing an ion conducting inorganic/organic hybrid membrane of claim 1.

3. An electrolyser containing an ion conducting inorganic/organic hybrid membrane of claim 1.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1-2. HR-TEM (High-Resolution Transmission Electron Microscopy) analyses of fluorine-doped titanium dioxide particles.

(2) FIG. 3-4. Scanning electron microscope (SEM) analyses of fluorine-doped titanium dioxide particles.

(3) FIG. 5. Change in the elastic modulus of the membranes in relation to temperature. The values of the elastic modulus at 25 C. are shown in insert a).

(4) FIG. 6. Change in tan =viscous modulus/elastic modulus with temperature for the membranes. Insert a) shows the values of tan for the maximum peak .

(5) FIG. 7. Polarization curves for MEA assembled from the membranes. The operating conditions are as follows: cell temperature 85 C.; temperature of the hydrogen flow and oxidizing agent flow 85 C.; relative moisture content of the reagents 100%; flow of hydrogen: 800 sccm; oxidizing agent used: air (top), pure oxygen (bottom); flow of oxidizing agent: 1700 sccm (air), 500 sccm (pure oxygen); reagent pressure: 5 bar (g).

(6) FIG. 8. Polarization curves for MEA assembled from the membranes. The reagent pressure is 2 bar (g); the other operating conditions are the same as those shown in the description for FIG. 7.

(7) FIG. 9. Maximum power density provided by MEA assembled from the membranes. Reagent pressure 5 bar (g), relative humidity of the reagents 100%. The remaining operating conditions are the same as those shown in the description for FIG. 7.

(8) FIG. 10. Maximum power density provided by MEA assembled from the membranes. Reagent pressure 2 bar (g), relative humidity of the reagents 100%. The remaining operating conditions are the same as those shown in the description for FIG. 7.

(9) FIG. 11. Polarization curves for the MEA assembled from the pure NAFION membrane with varying relative humidity of the reagents. Reagent pressure 2 bar (g); the other operating conditions are the same as those shown in the description for FIG. 7.

(10) FIG. 12. Polarization curves for the MEA assembled from 5% TiO.sub.2F membrane with varying relative humidity of the reagents. Reagent pressure 2 bar (g); the other operating conditions are the same as those shown in the description for FIG. 7.

(11) FIG. 13. Polarization curves for the MEA assembled from 10% TiO.sub.2F membrane with varying relative humidity of the reagents. Reagent pressure 2 bar (g); the other operating conditions are the same as those shown in the description for FIG. 7.

(12) FIG. 14. Polarization curves for the MEA assembled from 15% TiO.sub.2F membrane with varying relative humidity of the reagents. Reagent pressure 2 bar (g); the other operating conditions are the same as those shown in the description for FIG. 7.

(13) FIG. 15. Change in the maximum power density provided by the various MEA in relation to relative humidity at a reagent pressure of 2 bar (g). The other operating conditions are the same as those shown in the description for FIG. 7.