Flow cell for electrochemical ammonia synthesis

Abstract

The invention regards a flow cell for electrochemical ammonia synthesis, comprising a cathode, an anode, and an electrolyte chamber, wherein the anode comprises a HOR catalyst comprising bimetallic Pt, and/or wherein the electrolyte chamber comprises one or more spacers having a height defining a distance between the anode and cathode.

1 . A flow cell for electrochemical ammonia synthesis, comprising a cathode, an anode, and an electrolyte chamber, wherein the anode comprises a HOR catalyst comprising bimetallic Pt, and wherein the electrolyte chamber comprises one or more spacers having a height defining a distance between the anode and cathode. 
     
     
         2 . The flow cell according to  claim 1 , wherein the spacers are configured as separators diving the electrolyte chamber into two or more subchambers. 
     
     
         3 . The flow cell according to  any of the preceding claims , wherein the spacers have a height of between 50 μm-20 mm, more preferably between 500 μm-10 mm, and most preferably between 1 mm-6 mm, such as 2 or 4 mm. 
     
     
         4 . The flow cell according to  any of the preceding claims , wherein the spacers are elongated in one or more directions, and optionally shaped as bars. 
     
     
         5 . The flow cell according to  claim 4 , wherein the elongated spacers are intersecting each other at an angle to form a grid, optionally intersecting at a perpendicular angle. 
     
     
         6 . The flow cell according to  claim 5 , wherein the grid is sandwiched between a cathode plane and an anode plane. 
     
     
         7 . The flow cell according to  any of the preceding claims , wherein the electrolyte chamber comprises a cavity having two opposite ends defined by the anode and cathode, and side walls defined by an inner perimeter of a chamber frame, and wherein the spacers are detachably attached to the chamber frame. 
     
     
         8 . The flow cell according to  any of the preceding claims , wherein the electrolyte chamber comprises at least one fluid inlet and at least one fluid outlet such that the electrolyte chamber is configured for fluid replacement and/or circulation. 
     
     
         9 . The flow cell according to  claim 8 , wherein the fluid inlet and/or the fluid outlet comprise multiple lumen segments. 
     
     
         10 . The flow cell according to  claim 9 , wherein the fluid inlet and/or the fluid outlet comprise one or more first lumen segments extending in parallel and along an inner perimeter of a chamber frame, and one or more second lumen segments at an angle to the inner perimeter, such that the second lumen segment forms a chamber opening into the electrolyte chamber. 
     
     
         11 . The flow cell according to  claim 10 , wherein the fluid inlet and fluid outlet comprise oppositely located chamber openings. 
     
     
         12 . The flow cell according to  claim 11 , comprising multiple pairs of oppositely located chamber openings, wherein the pairs are located at a predefined distance from each other along the first lumen segment. 
     
     
         13 . The flow cell according to any of  claims 10-12 , wherein the chamber opening is a slit in parallel with a chamber plane. 
     
     
         14 . The flow cell according to any of  claims 10-13 , wherein the angle of the second lumen segment to the surface of the inner perimeter is diverging towards the inner perimeter of the chamber, optionally wherein the second lumen segment has a shape selected from the group of: trapezoid, and/or trapezoid with curved legs, such as circular curved legs. 
     
     
         15 . The flow cell according to any of  claims 9-14 , wherein one or more lumen segments are obtained by cutting and/or drilling. 
     
     
         16 . The flow cell according to any of  claims 2-15 , comprising between 1-40 separators, more preferably between 2-20 or 5-15 separators, and most preferably between 6-10 separators. 
     
     
         17 . The flow cell according to  any of the preceding claims , wherein the electrolyte chamber comprises flow circulation guides. 
     
     
         18 . The flow cell according to  claim 17 , wherein the spacers are configured as flow circulation guides. 
     
     
         19 . The flow cell according to  claim 18 , wherein the flow circulation guides are configured to generate a meandering fluid flow between the fluid inlet and fluid outlet. 
     
     
         20 . The flow cell according to  claim 18 , wherein the flow circulation guides are configured to generate a laminar flow between a fluid inlet and a fluid outlet. 
     
     
         21 . The flow cell according to  any of the preceding claims , wherein the electrolyte chamber is absent an ion conducting membrane. 
     
     
         22 . The flow cell according to  any of the preceding claims , wherein the bimetallic Pt is in combination with a metal selected from the groups 8-12, 14, 15, and combinations thereof, and optionally comprises a third or fourth metal. 
     
     
         23 . The flow cell according to  claim 22 , wherein the bimetallic Pt is in combination with a metal selected from the group of: Au, Ru, Rh, Pb, Bi, Sn, Sb, and combinations thereof. 
     
     
         24 . The flow cell according to  claim 23 , wherein the bimetallic Pt is in combination with Au, such as Pt—Au in atomic ratio 1:1, 1:2, 1:3, 1:4, 1:5, 2:3, 2:5, 2:1, 3:1, 4:1, 5:1, 3:2, 5:2. 
     
     
         25 . The flow cell according to  any of the preceding claims , wherein the electrolyte chamber contains an electrolyte comprising one or more proton shuttling additives, selected from the group of: alcohols, phenol, Li-phenol oxide, hydroquinone, phloroglucinol, 1-naphthol, pyridine, and any combinations thereof.