Production of gas diffusion electrodes comprising ion transport resins for electrochemical reduction of CO
Various embodiments include a gas diffusion electrode comprising: a metal M selected from the group consisting of: Ag, Au, Cu, and Pd; a binder; hydrophilic and hydrophobic pores and/or channels; and an anion transport material in the pores and/or channels.
1 . A gas diffusion electrode comprising:
a carrier;
a first catalyst layer disposed on the carrier, the first layer comprising a binder mixed with particles of at least one metal, and an anion transport material dispersed in the binder;
a second base layer comprising the at least one metal M and a second binder without the anion transport material, the second layer disposed between the carrier and the first layer; and
an overlap zone including an interface between the first catalyst layer and the second base layer defined by characteristics of both the first catalyst layer and the second base layer and having a thickness of 1-20 μm;
wherein the binder content in the first layer is less than in the second layer;
wherein the first layer and the second layer each comprise respective hydrophobic pores and/or channels;
wherein a first surface of the first layer faces the carrier and the second layer, and a second surface of the first layer faces away from the carrier and the second layer;
wherein the second surface has hydrophilic properties;
wherein the at least one metal is selected from the group consisting of: Ag, Au, Cu, and PD;
wherein the anion transport material comprises an ion exchange resin or a zeolite with a cation blocker function and conducting OH ions and/or HCO 3 through the first layer; and
wherein the anion transport material comprises no imidazolium-, pyridinium-, or β-hydrogen-containing groups.
2 . The gas diffusion electrode as claimed in claim 1 , wherein the anion transport material is disposed on a surface of the gas diffusion electrode.
3 . The gas diffusion electrode as claimed in claim 1 , wherein the anion transport material is stable at a pH of more than 7.
4 . The gas diffusion electrode as claimed in claim 1 , wherein the anion transport material includes quaternary alkylammonium groups.
5 . The gas diffusion electrode as claimed in claim 1 , wherein the anion transport material has been at least partly fluorinated.
6 . The gas diffusion electrode as claimed in claim 1 , wherein the anion transport material includes OH groups and/or NH 2 groups.
7 . The gas diffusion electrode as claimed in claim 1 ,
wherein the second layer includes 3-30% by weight of the binder; and
wherein the first layer includes 0-10% by weight of the binder.
8 . The gas diffusion electrode as claimed in claim 7 , wherein a proportion by weight of the ion transport material in the second layer is greater than the proportion by weight of the binder.