Process for the reduction of oxygen
View Patent ↗Process for the reduction of oxygen in aqueous chlorine- and/or chloride-containing solutions in the presence of a catalyst comprising nitrogen-doped carbon nanotubes.
1. Process for the reduction of oxygen, wherein, oxygen dissolved in aqueous chlorine- and/or chloride-containing solutions is reduced in the presence of a catalyst by application of an electric potential, with the catalyst comprising a proportion of nitrogen-doped carbon nanotubes as catalytically active component.
2. Process according to claim 1 , wherein the aqueous chlorine- and/or chloride-containing solutions are solutions of HCl with molecular chlorine dissolved therein or in gaseous form.
3. Process according to claim 1 , wherein the catalyst without a polymeric binder which optionally may be present comprises a proportion of at least 30% by weight of nitrogen-doped carbon nanotubes.
4. Process according to claim 1 , wherein that the nitrogen-doped carbon nanotubes comprise a proportion of at least 0.5% by weight of nitrogen.
5. Process according to claim 1 , wherein the catalyst comprises a polymeric binder in addition to the nitrogen-doped carbon nanotubes.
6. Process according to claim 5 , wherein the polymeric binder is a sulphonated tetrafluoroethylene polymer.
7. Process according to claim 5 wherein the catalyst comprises fillers.
8. Process according to claim 1 , wherein the catalyst comprises other catalytically active components in addition to the nitrogen-doped carbon nanotubes.
9. Process according to claim 1 , carried out at a temperature of 0-200° C.
10. Process according to claim 1 , operated at current densities of greater than 0.01 kA/m 2 .
11. Process according to claim 1 , wherein the aqueous chlorine- and/or chloride-containing solution is formed over the catalyst by passing a gas stream comprising molecular oxygen and gaseous HCl and also, optionally, water vapor over the catalyst.
12. Process according to claim 1 , wherein the oxygen is reduced in the presence of a catalyst by application of an electric potential in a first reaction zone, with the catalyst comprising a proportion of nitrogen-doped carbon nanotubes as catalytically active component, and chloride is oxidized to chlorine in a second reaction zone.