Anode for reducing oxygen generation in the electrolysis of hydrogen chloride

Claim 3

The method of claim 1, wherein the thickness of the anode catalyst is about 6.0 microns to about 50 microns.

Claim 4

The method of claim 1, wherein the thickness of the anode catalyst is about 10.0 microns to about 13.0 microns.

Claim 5

The method of claim 1, wherein the porosity is increased by increasing the particle size of powder components in the anode material.

Claim 6

The method according to claim 1 wherein the liquid and gas permeable porous anode has a void volume ranging between 60 and 90 percent.

Claim 7

The method according to claim 1 wherein void volume of the porous anode is between 60 and 75 percent.

Claim 8

The method according to claim 1 wherein the void volume of the porous anode is substantially 75 percent.

Claim 11

The method of claim 8, wherein the thickness of the anode is about 10.0 microns to about 13.0 microns.

Claim 12

In an electrode for the electrolysis of hydrogen chloride in an electrolytic cell having a cation transporting solid polymer electrolyte membrane, a porous gas and liquid permeable catalytic anode having tortuous pores extending therethrough said anode being adapted to be bonded to one surface of a solid polymer electrolyte membrane, whereby chloride ions diffuse through the pores from one surface of the electrod towards the cation transporting membrane to which the electrode is adapted to be bonded, to allow the chloride ions to be oxidized there to form chlorine gas the improvement comprising said catalytic anode electrode being constructed to maximize the transport rate of hydrogen chloride and chloride ions into and within said pores which comprises a structure in which the diffusion path length of the pores is a function of the thickness and porosity of the anodes and the tortuosity of the pores whereby the rate of transfer of the chloride ions to the electrodes is sufficient to sustain cell current by discharge of the chloride ion while minimizing co-evolution of other electrolysis products.

Claim 13

In an electrode for the electrolysis of hydrogen chloride in an electrolytic cell having a cation transporting solid polymer electrolyte membrane, a porous gas and liquid permeable catalytic anode having tortuous pores extending therethrough said anode being adapted to be bonded to one surface of a solid polymer electrolyte membrane, whereby chloride ions diffuse through the pores from one surface of the electrod towards the cation transporting membrane to which the electrode is adapted to be bonded, to allow the chloride ions to be oxidized there to form chlorine gas the improvement comprising said catalytic anode electrode being constructed to maximize the transport rate of hydrogen chloride and chloride ions into and within said pores which comprises a structure in which the diffusion path length of the pores is a function of the thickness and porosity of the anodes and the tortuosity of the pores whereby the rate of transfer of the chloride ions to the electrodes is sufficient to sustain cell current by discharge of the chloride ion while minimizing co-evolution of other electrolysis products.

Claim 14

The electrode of claim 10, wherein the thickness of the anode material is about 6.0 microns to about 50.0 microns.

Claim 15

The electrode of claim 10, wherein the thickness of the anode material is about 10.0 microns to about 13.0 microns.

Claim 16

The electrode according to claim 10 wherein the porous electrode has a void volume in between 60 and 90 percent.

Claim 17

The electrode according to claim 10 wherein the porous electrode porosity has a void volume between 60 and 75 percent.

Claim 18

The porous electrode according to claim 10 wherein the porosity of the electrode is substantially at 75 percent.

Claim 19

In an apparatus for the generation of chlorine from hydrogen chloride by electrolysis when the electrolysis is carried out in an electrolytic cell having a cation transporting solid polymer electrolyte membrane a porous, gas and liquid permeable catalytic anode bonded to one surface and a cathode bonded to the other surface of the membrane, the cation transporting membrane dividing the electrolytic cell into an anode chamber on the side of the membrane having the anode and into a cathode chamber on the side of the membrane having the cathode, means for providing electrical current at the anode and the cathode, feed means for feeding an aqueous hydrogen chloride anolyte into the anode chamber, means for removing chlorine and depleted hydrogen chloride anolyte from the anode chamber, and means for removing hydrogen from the cathode chamber, the improvement comprising an anode of a thickness of about 6.0 microns to 50.0 microns to minimize the diffusion path length to provide an increase in the rate of transport of hydrogen chloride and chloride ions towards the surface of the membrane.

Claim 20

In an apparatus for the generation of chlorine from hydrogen chloride by electrolysis when the electrolysis is carried out in an electrolytic cell having a cation transporting solid polymer electrolyte membrane a porous, gas and liquid permeable catalytic anode bonded to one surface and a cathode bonded to the other surface of the membrane, the cation transporting membrane dividing the electrolytic cell into an anode chamber on the side of the membrane having the anode and into a cathode chamber on the side of the membrane having the cathode, means for providing electrical current at the anode and the cathode, feed means for feeding an aqueous hydrogen chloride anolyte into the anode chamber, means for removing chlorine and depleted hydrogen chloride anolyte from the anode chamber, and means for removing hydrogen from the cathode chamber, the improvement comprising an anode of a thickness of about 6.0 microns to 50.0 microns to minimize the diffusion path length to provide an increase in the rate of transport of hydrogen chloride and chloride ions towards the surface of the membrane.

Claim 21

The apparatus of claim 16, wherein the thickness of the anode material is about 10.0 microns to about 13.0 microns.