new findings

Rice research team's study keeps CO2-to-fuel devices running 50 times longer

Ahmad Elgazzar, Haotian Wang and Shaoyun Hao were members of a Rice University team that recently published findings on how acid bubbling can improve CO2 reduction systems. Photo courtesy Rice.

In a new study published in the journal Science, a team of Rice University researchers shared findings on how acid bubbles can improve the stability of electrochemical devices that convert carbon dioxide into useful fuels and chemicals.

The team led by Rice associate professor Hoatian Wang addressed an issue in the performance and stability of CO2 reduction systems. The gas flow channels in the systems often clog due to salt buildup, reducing efficiency and causing the devices to fail prematurely after about 80 hours of operation.

“Salt precipitation blocks CO2 transport and floods the gas diffusion electrode, which leads to performance failure,” Wang said in a news release. “This typically happens within a few hundred hours, which is far from commercial viability.”

By using an acid-humidified CO2 technique, the team was able to extend the operational life of a CO2 reduction system more than 50-fold, demonstrating more than 4,500 hours of stable operation in a scaled-up reactor.

The Rice team made a simple swap with a significant impact. Instead of using water to humidify the CO2 gas input into the reactor, the team bubbled the gas through an acid solution such as hydrochloric, formic or acetic acid. This process made more soluble salt formations that did not crystallize or block the channels.

The process has major implications for an emerging green technology known as electrochemical CO2 reduction, or CO2RR, that transforms climate-warming CO2 into products like carbon monoxide, ethylene, or alcohols. The products can be further refined into fuels or feedstocks.

“Using the traditional method of water-humidified CO2 could lead to salt formation in the cathode gas flow channels,” Shaoyun Hao, postdoctoral research associate in chemical and biomolecular engineering at Rice and co-first author, explained in the news release. “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.”

The Rice team believes the work can lead to more scalable CO2 electrolyzers, which is vital if the technology is to be deployed at industrial scales as part of carbon capture and utilization strategies. Since the approach itself is relatively simple, it could lead to a more cost-effective and efficient solution. It also worked well with multiple catalyst types, including zinc oxide, copper oxide and bismuth oxide, which are allo used to target different CO2RR products.

“Our method addresses a long-standing obstacle with a low-cost, easily implementable solution,” Ahmad Elgazzar, co-first author and graduate student in chemical and biomolecular engineering at Rice, added in the release. “It’s a step toward making carbon utilization technologies more commercially viable and more sustainable.”

A team led by Wang and in collaboration with researchers from the University of Houston also shared findings on salt precipitation buildup and CO2RR in a recent edition of the journal Nature Energy. Read more here.

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A View From HETI

Houston Innovation Awards nominations are open through August 31. Photo courtesy of InnovationMap

Calling all Houston energy innovators: The Houston Innovation Awards return this fall to celebrate the best and brightest in the Houston innovation ecosystem, and that includes those leading the energy transition.

Presented by InnovationMap, the fifth annual Houston Innovation Awards will take place November 5 at TMC Helix Park.

The awards program will honor the top startups and innovators in Houston across 10 categories, and we're asking you to nominate the most deserving Houston innovators and innovative companies, including those in the energy transition sector.

This year's categories are:

  • Minority-founded Business, honoring an innovative startup founded or co-founded by BIPOC or LGBTQ+ representation.
  • Female-founded Business, honoring an innovative startup founded or co-founded by a woman.
  • Energy Transition Business, honoring an innovative startup providing a solution within renewables, climatetech, clean energy, alternative materials, circular economy, and beyond.
  • Health Tech Business, honoring an innovative startup within the health and medical technology sectors.
  • Deep Tech Business, honoring an innovative startup providing technology solutions based on substantial scientific or engineering challenges, including those in the AI, robotics, and space sectors.
  • Startup of the Year (People's Choice), honoring a startup celebrating a recent milestone or success. The winner will be selected by the community via an interactive voting experience.
  • Scaleup of the Year, honoring an innovative later-stage startup that's recently reached a significant milestone in company growth.
  • Incubator/Accelerator of the Year, honoring a local incubator or accelerator that is championing and fueling the growth of Houston startups.
  • Mentor of the Year, presented by Houston Community College, honoring an individual who dedicates their time and expertise to guide and support budding entrepreneurs.
  • Trailblazer, honoring an innovator who's made a lasting impact on the Houston innovation community.

Nominations may be made on behalf of yourself, your organization, and other leaders and institutions in the local innovation scene. The nomination period closes on August 31, so don't delay — nominate today at this link, or fill out the embedded form below.

A panel of esteemed judges will review the nominations, and determine the finalists and winners. Finalists will be unveiled on InnovationMap.com on September 30, and the 2025 Houston Innovation Awards winners will be announced live at an event on November 5.

Tickets will go on sale this fall. Stay tuned for that announcement.

Interested in Innovation Awards sponsorship opportunities? Please contact sales@innovationmap.com.

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