Description

A complete 25 cm² CO2 electrolyzer. Includes the following components: Titanium anode flow field, 904 L Stainless Steel cathode flow field, catalyst covered electrodes for anodes and cathodes of 25 cm2 cell, Sustainion^® membrane, nuts, bolts, o-rings and insulating kit, and electrolyzer testing service.

Note: these are built to order. Shipment usually occurs 3-5 days after order is placed.

Instructions for use

Initial set up for DM Alkaline CO₂ Electrolyzer Cell

• System set up (recommended)
  Typically, the system setup uses a peristaltic pump to circulate a 10mM KHCO₃ aqueous solution (from the reservoir) into the anode chamber at flowrate of 25 mL/min. The suggested tubing used is a 1/4” OD, 1/8” ID PTFE tubing. Pure CO₂ from a cylinder is humidified with water using a bottle humidifier (sold separately) and then fed to the cathode chamber at a flow rate of 150 sccm.
• Fluid Connections
  i) Cathode: remove the nuts from compression tubing and remove black rubber rod from the nut, connect the tubing (PTFE, 1/4”OD) from CO2 humidifier to the compression fitting at the top of cathode (stainless steel flow field); connect another tubing (PTFE, 1/4” OD)to the compression fitting at the bottom of cathode, route to the catholyte collector and then to THE EXHAUST. Please note that CO is poisonous, so please do not emit or release the cathode product gas into lab or working area.
  ii) Anode: Remove the nuts from the compression fittings and remove the black rubber rod from the nut. Then push the tubing from the pump tubing 1/4” (OD) PTFE through the nuts, turn the nuts with tubing inside onto the compression fitting at the bottom. Connect another tubing (1/4” OD, PTFE) to the compression fitting at the top, and route back the the anolyte reservoir. Tighten the nuts with fingers only.
• Power Connections
  Locate the threaded hole for wire connection on top of the cell (smaller through-hole 8-32 thread). Then connect the ring terminal with the Phillips round head screw. Use this same procedure for both anode and cathode.

  Figure 1. The electrolyzer setup

  Figure 2. Diagram of the 25 cm2 cell

  Cell Testing and Operation

  Begin pumping a 10mM KHCO₃ aqueous solution from reservoir at a rate of 25mL/min to the inlet (at the bottom) of the anode chamber and feeding CO₂ through a bottle humidifier to the inlet (at the top) of the cathode chamber. Connect the anode electrical lead (red) and cathode lead (black) to the positive and negative connections, respectively, on the power supply with electric wires/cables (not included). Set the power supply voltage at 3-3.2V and slowly begin increasing the current to a setting of 5 A (0.2A/cm<sup<2). The cell current will reach the desired 5A in a few min or hours depending on the cell membrane and electrode conditioning. Testing can also be done with potentiostat, but the connections depend on the testing protocol.