CO₂ Electrolyzer Lifespan: Rice University 50x Boost
- Houston - A surprisingly simple tweak has yielded a major improvement in the stability of electrochemical devices designed to convert carbon dioxide into usable fuels and chemicals.
- The study, published in Science, addresses a critical issue in CO2 reduction systems: salt buildup.This accumulation clogs gas flow channels, reduces efficiency, and leads to premature device failure.
- Electrochemical CO2 reduction (CO2RR) is an emerging technology that uses electricity, ideally from renewable sources, to transform CO2 into valuable products like carbon monoxide, ethylene, or alcohols.
Rice University researchers have dramatically boosted teh lifespan of CO₂ electrolyzers with a simple acid bubbler, achieving a remarkable 50x increase in operational time. This breakthrough prevents salt buildup, the primary cause of device failure in electrochemical CO₂ reduction (CO2RR) systems. By acid-humidifying the CO₂ before it enters the reactor, scientists are unlocking a more stable and efficient way to convert carbon dioxide into valuable fuels and chemicals. This method works effectively across various catalysts, making it scalable for industrial applications. News Directory 3 highlights how this innovation is poised to accelerate adoption of CO₂ conversion technologies. What are the next generation upgrades?
Simple Acid Bubbler Dramatically Improves CO2 Conversion, Study Shows
Updated June 23, 2025
Houston – A surprisingly simple tweak has yielded a major improvement in the stability of electrochemical devices designed to convert carbon dioxide into usable fuels and chemicals. Researchers at Rice University discovered that bubbling CO2 through an acid solution before it enters the reactor dramatically extends the system’s operational life.
The study, published in Science, addresses a critical issue in CO2 reduction systems: salt buildup.This accumulation clogs gas flow channels, reduces efficiency, and leads to premature device failure. By using what they term “acid-humidified CO2,” the team achieved over 4,500 hours of stable operation in a scaled-up reactor, a 50-fold increase compared to standard methods. This marks a significant step toward commercially viable CO2 conversion.
Electrochemical CO2 reduction (CO2RR) is an emerging technology that uses electricity, ideally from renewable sources, to transform CO2 into valuable products like carbon monoxide, ethylene, or alcohols. These can then be refined into fuels or used in industrial processes,potentially turning a major pollutant into a valuable resource. Though,the technology has been hampered by instability issues,especially the accumulation of potassium bicarbonate salts in gas flow channels.
Haotian Wang, associate professor at Rice University and the study’s corresponding author, said salt precipitation blocks CO2 transport and floods the gas diffusion electrode, leading to performance failure.He added that this typically occurs within a few hundred hours, far short of commercial requirements.
The Rice team’s solution involves bubbling the CO2 gas input through an acid solution, such as hydrochloric, formic, or acetic acid, instead of water. The trace amounts of acid vapor carried into the cathode reaction chamber alter the local chemistry.The resulting salts are much more soluble than potassium bicarbonate, preventing crystallization and channel blockage.
The results were significant. A system using a silver catalyst operated stably for over 2,000 hours in a lab-scale device and more than 4,500 hours in a scaled-up electrolyzer. In contrast, systems using standard water-humidified CO2 failed after approximately 80 hours due to salt buildup. The acid-humidified method also proved effective across multiple catalyst types, including zinc oxide, copper oxide, and bismuth oxide, each targeting different CO2RR products. The researchers also demonstrated that the method could be scaled without compromising performance, maintaining energy efficiency and avoiding salt blockage over extended periods.
the team observed minimal corrosion or damage to the anion exchange membranes, which are typically sensitive to chloride, by maintaining low acid concentrations. The approach is also compatible with commonly used membranes and materials, enhancing its potential for integration into existing systems. Using custom-built reactors with obvious flow plates, the team observed salt formation in real time. Salt crystals formed within 48 hours under conventional water humidification. However, with acid-humidified CO2, no significant crystal accumulation was observed, and any small deposits dissolved and were carried out of the system.
“Using the traditional method of water-humidified CO2 could lead to salt formation in the cathode gas flow channels,” said Shaoyun Hao, postdoctoral research associate at Rice. “We hypothesized — and confirmed — that acid vapor could dissolve the salt and convert the low solubility KHCO3 into salt with higher solubility, thus shifting the solubility balance just enough to avoid clogging without affecting catalyst performance.”
What’s next
This work paves the way for more durable and scalable CO2 electrolyzers, a critical need for deploying the technology at industrial scales as part of carbon capture and utilization strategies. The simplicity of the approach means it can be adopted without significant redesigns or added costs, potentially accelerating the adoption of CO2 conversion technologies.