Catalyst System for Catalyzed Electrochemical Reactions and Preparation Thereof, Applications and Uses Thereof

Abstract

A catalyst system for catalyzed electrochemical reactions, in particular the electrochemical conversion of carbon dioxide into valuable chemical products, such as carboxylates and carboxylic acids, comprises a catalyst, wherein the catalyst comprises bismuth and indium. The catalyst system can be a component of a gas diffusion electrode, that can be used as the cathode electrode in an electrochemical cell.

1 . A catalyst system for catalyzed electrochemical reactions, comprising a catalyst, wherein the catalyst comprises 5-94 wt. % bismuth and 6-95 wt. % indium, based on a total amount of bismuth and indium. 
     
     
         2 . A catalyst system according to  claim 1 , further comprising an electrically conductive support. 
     
     
         3 . A catalyst system according to  claim 1 , wherein the amount of bismuth is in a range of 10-90 wt. %, based on the total amount of bismuth and indium. 
     
     
         4 . A catalyst system according to  claim 1 , wherein the amount of bismuth is in a the range of 40-60 wt. %, based on the total amount of bismuth and indium 
     
     
         5 . A catalyst system according to  claim 2 , wherein the conductive support comprises a porous structure of carbon particles. 
     
     
         6 . A gas-diffusion electrode comprising: a gas-diffusion layer on a conductive substrate, the gas-diffusion layer comprising a catalyst system for catalyzed electrochemical reactions, comprising a catalyst, wherein the catalyst comprises 5-94 wt. % bismuth and 6-95 wt. % indium, based on a total amount of bismuth and indium. 
     
     
         7 . A gas-diffusion electrode according to  claim 6 , wherein the catalyst system is bonded to the conductive substrate by a hydrophobic binder. 
     
     
         8 . An electrochemical cell comprising:
 at least one gas chamber and at least one liquid chamber, which chambers are separated by a gas-diffusion electrode, the gas-diffusion electrode including a gas-diffusion layer on a conductive substrate, the gas-diffusion layer comprising a catalyst system for catalyzed electrochemical reactions, the catalyst system comprising a catalyst, wherein the catalyst comprises 5-94 wt. % bismuth and 6-95 wt. % indium, based on a total amount of bismuth and indium.   
     
     
         9 - 10 . (canceled) 
     
     
         11 . A method of electrocatalytically reducing carbon dioxide, comprising
 introducing an anolyte to a first cell compartment of an electrochemical cell, the first cell compartment comprising an anode;   introducing a catholyte and carbon dioxide to a second cell compartment of the electrochemical cell, the second cell compartment comprising a cathode, and   applying an electrical potential between the anode and the cathode sufficient to reduce the carbon dioxide to a reduced reaction product,   wherein the cathode comprises a catalyst system, the catalyst system for catalyzed electrochemical reactions, comprising a catalyst, wherein the catalyst comprises 5-94 wt. % bismuth and 6-95 wt. % indium, based on a total amount of bismuth and indium.   
     
     
         12 . A method according to  claim 11 , wherein the cathode is a gas-diffusion electrode, the gas-diffusion electrode comprising: a gas-diffusion layer on a conductive substrate, the gas-diffusion layer including the catalyst system. 
     
     
         13 . A method according to  claim 11 , wherein carbon dioxide is reduced to a reaction product selected from carboxylates and carboxylic acids. 
     
     
         14 . A method according to  claim 11 , wherein carbon dioxide is reduced to formate or formic acid in an aqueous medium. 
     
     
         15 . A method according to  claim 11 , wherein carbon dioxide is reduced to oxalate or oxalic acid in a non-aqueous medium.