Supported electrocatalyst for enhanced electrochemical ammonia production

Abstract

Embodiments of the present technology may include electrochemical cell systems for producing ammonia. The electrochemical cell system may include a working electrode submerged in an electrolyte. The working electrode may include an iron foam (IF) substrate. The working electrode may also include a plurality of iron vanadate (FeVO 4 ) nanoparticles deposited on the IF substrate.

What is claimed is: 
     
         1 . An electrochemical cell system for producing ammonia, the electrochemical cell system comprising:
 a working electrode submerged in an electrolyte, the working electrode comprising:
 an iron foam (IF) substrate; and 
 a plurality of iron vanadate (FeVO 4 ) nanoparticles deposited on the IF substrate. 
   
     
     
         2 . The electrochemical cell system of  claim 1 , wherein the plurality of FeVO 4  nanoparticles are formed from a hydrothermal method. 
     
     
         3 . The electrochemical cell system of  claim 1 , wherein the plurality of FeVO 4  nanoparticles are deposited on the IF substrate by drop casting in a nanoink solution. 
     
     
         4 . The electrochemical cell system of  claim 1 , wherein the electrolyte comprises diatomic nitrogen (N 2 ). 
     
     
         5 . The electrochemical cell system of  claim 1 , wherein the electrolyte is continuously fed diatomic nitrogen (N 2 ) during an ammonia producing process. 
     
     
         6 . The electrochemical cell system of  claim 1 , wherein the electrolyte comprises sodium sulfate (Na 2 SO 4 ). 
     
     
         7 . The electrochemical cell system of  claim 1 , further comprising:
 a counter electrode configured to produce a drive current with the working electrode; and   a reference electrode for measuring an electric potential associated with the working electrode.   
     
     
         8 . The electrochemical cell system of  claim 7 , wherein:
 the counter electrode is platinum; and   the reference electrode is Ag/AgCl.   
     
     
         9 . A method for producing ammonia, the method comprising:
 depositing a plurality of iron vanadate (FeVO 4 ) nanoparticles on an iron foam (IF) substrate to form a working electrode of an electrochemical cell;   submerging the working electrode in an electrolyte; and   applying a potential difference between the working electrode and a counter electrode to produce the ammonia.   
     
     
         10 . The method of  claim 9 , wherein applying the potential difference comprises applying the potential difference between the working electrode and the counter electrode so that the counter electrode is at a higher potential than the working electrode. 
     
     
         11 . The method of  claim 10 , wherein applying the potential difference comprises applying the potential difference between the working electrode and the counter electrode so that the counter electrode is less than 1 reversible hydrogen electrode Volt (V RHE ) higher than the working electrode. 
     
     
         12 . The method of  claim 9 , further comprising forming the plurality of FeVO 4  nanoparticles from a hydrothermal method. 
     
     
         13 . The method of  claim 9 , wherein depositing the plurality of FeVO 4  nanoparticles on the IF substrate comprises drop casting the plurality of FeVO 4  nanoparticles in a nanoink solution on the IF substrate. 
     
     
         14 . The method of  claim 9 , wherein the electrolyte comprises diatomic nitrogen (N 2 ). 
     
     
         15 . The method of  claim 9 , further comprising continuously feeding the electrolyte diatomic nitrogen (N 2 ). 
     
     
         16 . The method of  claim 9 , wherein the electrolyte comprises sodium sulfate (Na 2 SO 4 ). 
     
     
         17 . The method of  claim 9 , further comprising:
 producing a drive current between the working electrode and the counter electrode; and   measuring the applied potential difference using a reference electrode.   
     
     
         18 . The method of  claim 17 , wherein:
 the counter electrode is platinum; and   the reference electrode is Ag/AgCl.   
     
     
         19 . The method of  claim 9 , wherein applying the potential difference comprises applying the potential difference between the working electrode and the counter electrode to produce ammonia at an ammonia yield greater than 
       
         
           
             
               4 
               ⁢ 
                  
               
                 
                   μ 
                   ⁢ 
                   g 
                 
                 h 
               
               / 
               
                 mg 
                 . 
               
             
           
         
       
     
     
         20 . The method of  claim 9 , wherein applying the potential difference comprises applying the potential difference between the working electrode and the counter electrode to produce ammonia with a Faradaic Efficiency greater than 10%.