Systems and methods for variable pressure electrochemical carbon dioxide reduction

Abstract

Electrochemical devices, such as membrane electrode assemblies and electrochemical reactors, are described herein, as well as and methods for the conversion of reactants such as carbon dioxide to value-added products such as ethanol. In certain aspects, the membrane electrode assemblies are configured to allow for distributed pressure along the cathodic side of a membrane electrode assembly is described. The pressure vessel acts as a cathode chamber, both for the feed of reactant carbon dioxide as well as collection of products. The designs described herein improves the safety of high pressure electrochemical carbon dioxide reduction and allows for varied pressures to be used, in order to optimize reaction conditions. Configurations optimized for producing preferred products, such as ethanol, are also described.

1 . An electrochemical cell, comprising:
 an electrode assembly comprising;
 an anode endplate; 
 a cathode endplate; and 
 a polymer electrolyte membrane having a cathodic side and an anodic side disposed between the anode endplate and the cathode endplate; and 
 a fluid surrounding the electrode assembly: 
   wherein the cathodic side of the polymer electrolyte membrane is in open fluid communication with the fluid surrounding the electrode assembly.   
     
     
         2 . The electrochemical cell of  claim 1 , further comprising a cathode catalyst disposed on the cathodic side of the polymer electrolyte membrane. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . An electrochemical reactor, comprising:
 a pressure vessel; and   an electrode stack comprising one or more electrochemical cells according to  claim 1 .   
     
     
         6 . The electrochemical reactor of  claim 5 , wherein the cathodic side of the polymer electrolyte membrane is open to the atmosphere of the pressure vessel. 
     
     
         7 . The electrochemical reactor of  claim 5 , wherein the electrode stack is completely contained within the pressure vessel. 
     
     
         8 . The electrochemical reactor of  claim 5 , wherein the pressure vessel comprises a reactant input fitting and a product output fitting. 
     
     
         9 - 15 . (canceled) 
     
     
         16 . The electrochemical cell of  claim 1 , wherein the fluid surrounding the electrode assembly is a catholyte comprising CO 2 .