Electrolysis

Gamry Instruments has a large variety of potentiostats/galvanostats for the testing of electrolyzers. We have also partnered with Kolibrik.net to expand our product line to provide a larger range of options for higher power devices. All of these potentiostats/galvanostats are capable of performing electrochemical impedance spectroscopy, a very well known technique for analyzing systems during operation. Additionally, all of the potentiostats/galvanostats are isolated from Earth ground, making measurements on grounded cells (like electrolyzers!) very easy.

The standard product lineup covers material testing all the way up to engineering studies. Voltages can range from 5V up to 1000V and maximum currents from 600mA to 2000A. We even have capabilities to monitor both half cells simultaneously in a single cell configuration or we have the ability to monitor up to 1000 channels all at once.

Nowhere else will you find this kind of flexibility in a product lineup. Gamry and Kolibrik have you covered.

Electrolysis is a process that involves the use of a potentiostat or galvanostat to push electrical current through an electrochemical cell to drive a non-spontaneous electrochemical reaction. The electrochemical cell contains an electrolyte (i.e. solvent that with ions) that participates in the electrochemical reaction. One or more of these components may undergo electrolysis.

Electrolysis can involve two or three electrodes. The two-electrode process involves an anode and a cathode, where oxidation and reduction take place, respectively. While simpler in principle, the two-electrode setup sacrifices accuracy and control. A three-electrode process involves an anode, cathode, and reference electrode. The addition of a reference electrode allows for an accurate determination of the working electrode potential, thus giving more control over the process.
The production of hydrogen gas (H2) from water is a very good example of electrolysis. In the overall reaction, two molecules of water produce two molecules of H2 and one molecule of O2 as show below:

2 H₂O(l) → 2 H₂(g) + O₂(g)

Remember, this is the overall reaction though. Individually, there are half-reactions occurring at the anode and cathode. These are:

Anode: 2 H₂O(l) → O₂(g) + 4 H+(aq) + 4 e-
Cathode: 4 H₂O(l) + 4 e- → 2 H₂(g) + 4 OH-(aq)

As the world moves to add alternative sources of energy, hydrogen can play an important role in a more sustainable energy economy. Another method to produce hydrogen can come from the electrolysis of ammonia.

Ammonia electrolysis works by splitting ammonia (NH₃) into H₂ and nitrogen gas (N2). The overall reaction can be written as:

2 NH_¬3(l)→ 3 H₂(g) + N₂(g)

Ammonia is a low-cost and readily available feedstock, making ammonia electrolysis a viable, low-cost method for transport and production of hydrogen. Finally, this process can also be powered by renewable energy sources such as solar or wind power.

One final example of an electrolytic process that isn’t as commercially viable as of yet but could have an incredibly large impact on reducing greenhouse gas emissions is the electrolysis of carbon dioxide (CO₂). New catalyst materials are being developed to improve the selectivity and activity of the electrode reactions, while novel reactor designs and operating conditions are being explored to enhance the performance and durability of the electrolysis cells. While the practical applications of CO₂ electrolysis are still in the early stages of development, it has the potential to play an important role in the transition to a more sustainable energy economy.

Many Gamry systems can meet the needs of a electrolyzer researcher. The Interface 1010E, with currents up to 1 A, is a great system for studying materials or smaller setups.  The Interface 5000E is a great single cell system that can provide up to 5A @ 6 V.  The Interface 5000E can also measure both half cells simultaneously in a three-electrode system. Our Reference 3000/3000AE along with the Reference 30K Booster for extra current is an ideal solution for fuel cells that operate up to 30 A total current, and up to 20 V in the stack.  It is capable of running both DC and AC testing. Both the Interface line and Reference line of instruments can be configured into bipotentiostat setups for running RRDE experiments.  

For even higher currents, Gamry has partnered with Kolibrik.net* to provide capabilities up to 100A or more! Several Kolibrik potentiostats/galvanostats exist for single cells and short stacks. There are standard systems for 5V/20A, 5V/50A, 5V/100A, 10V/20A, and 10V/50A. For large systems, up to 1000V and 2000A with up to 1000 channels, Kolibrik has the MegaEIS system.

We also have the LPI1010 (combined with an Interface 1010E) that interfaces with specific electronic loads or power supplies to provide higher voltages or higher currents (or both). The LPI1010 can be very useful when you need to test a variety of configurations.

So, no matter what your power needs, from small scale materials studies to scale-up engineering studies, we have a solution for you.  Give us a call to find out more.

*Gamry is able to provide Kolibrik.net in North America, China, Italy, Belgium, The Netherlands, Luxembourg, Slovakia, and the Czech Republic. Other countries should contact Kolibrik directly.