Gas diffusion electrode for carbon dioxide utilization, method for producing same, and electrolytic cell having a gas diffusion electrode

Abstract

A gas diffusion electrode for carbon dioxide utilization, including a metal substrate and an electrically conductive catalyst layer, which is applied to the metal substrate and has hydrophilic pores and / or channels and hydrophobic pores and / or channels, wherein the catalyst layer includes metal particles and a first polymeric binding material; and a porous gas diffusion layer containing the first polymeric binding material is formed on the surface of the catalyst layer. A method produces a gas diffusion electrode for CO2 utilization and an electrolytic cell has a corresponding gas diffusion electrode.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2019 / 064572 filed 5 Jun. 2019, and claims the benefit thereof. The International Application claims the benefit of German Application No. DE 10 2018 210 457.3 filed 27 Jun. 2018. All of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The present invention relates to a gas diffusion electrode for utilization of carbon dioxide and also a process for producing a gas diffusion electrode. The invention further relates to an electrolysis system having a corresponding gas diffusion electrode.BACKGROUND OF INVENTION[0003]At present, about 80% of worldwide energy consumption is covered by the combustion of fossil fuels. About 34000 million metric tons of the greenhouse gas carbon dioxide (CO2) are emitted into the atmosphere via these combustion processes every year worldwide. The major part of carbon dioxide is disposed...

AI Technical Summary

Benefits of technology

The patent describes a gas diffusion electrode made with a fluoropolymer binder, which improves the efficiency of an electrochemical system and makes the production process more competitive. The use of polyvinylidene fluoride (PVDF) is particularly useful. This electrode design can lead to higher productivity and reduced costs of production.

Problems solved by technology

However, CO2 is thermodynamically in a very low position and can therefore be reduced again to give usable products only with difficulty.

However, this process cannot readily be carried over to an industrial scale.

A copy of the natural photosynthesis process using industrial photocatalysis has hitherto not been sufficiently efficient.

A typical problem occurring in the case of gas diffusion electrodes used for CO2 reduction which are in contact with an electrolyte (for example KHCO3, K2SO4, KOH or mixtures thereof) is that of avoiding undesirable secondary reactions in the electrolyte-side region of the gas diffusion electrode.

However, gas diffusion electrodes produced in this way tend to have the limiting pore diameter only within the gas diffusion electrode but not on the surface.

The pore size diameter facing the electrolyte side is comparatively large compared to gas diffusion electrodes having a gas diffusion layer, so that undesirable flooding behavior of the pore system is observed.

This effect leads to an undesirable decrease in the Faraday efficiency of the gaseous products CO or ethylene.

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