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 recently shared findings on salt precipitation buildup and CO2RR in a recent edition of the journal Nature Energy.

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This article originally appeared on our sister site, EnergyCapitalHTX.com.

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How Houston innovators played a role in the historic Artemis II splashdown

safe landing

Research from Rice University played a critical role in the safe return of U.S. astronauts aboard NASA’s Artemis II mission this month.

Rice mechanical engineer Tayfun E. Tezduyar and longtime collaborator Kenji Takizawa developed a key computational parachute fluid-structure interaction (FSI) analysis system that proved vital in NASA’s Orion capsule’s descent into the Pacific Ocean. The FSI system, originally developed in 2013 alongside NASA Johnson Space Center, was critical in Orion’s three-parachute design, which slowed the capsule as it returned to Earth, according to Rice.

The model helped ensure that the parachute design was large enough to slow the capsule for a safe landing while also being stable enough to prevent the capsule from oscillating as it descended.

“You cannot separate the aerodynamics from the structural dynamics,” Tezduyar said in a news release. “They influence each other continuously and even more so for large spacecraft parachutes, so the analysis must capture that interaction in a robustly coupled way.”

The end result was a final parachute system, refined through NASA drop tests and Rice’s computational FSI analysis, that eliminated fluctuations and produced a stable descent profile.

Apart from the dynamic challenges in design, modeling Orion’s parachutes also required solving complex equations that considered airflow and fabric deformation and accounted for features like ringsail canopy construction and aerodynamic interactions among multiple parachutes in a cluster.

“Essentially, my entire group was dedicated to that work, because I considered it a national priority,” Tezduyar added in the release. “Kenji and I were personally involved in every computer simulation. Some of the best graduate students and research associates I met in my career worked on the project, creating unique, first-of-its-kind parachute computer simulations, one after the other.”

Current Intuitive Machines engineer Mario Romero also worked on Orion during his time at NASA. From 2018 to 2021, Romero was a member of the Orion Crew Capsule Recovery Team, which focused on creating likely scenarios that crewmembers could encounter in Orion.

The team trained in NASA’s 6.2-million-gallon pool, using wave machines to replicate a range of sea conditions. They also simulated worst-case scenarios by cutting the lights, blasting high-powered fans and tipping a mock capsule to mimic distress situations. In some drills, mock crew members were treated as “injured,” requiring the team to practice safe, controlled egress procedures.

“It’s hard to find the appropriate descriptors that can fully encapsulate the feeling of getting to witness all the work we, and everyone else, did being put into action,” Romero tells InnovationMap. “I loved seeing the reactions of everyone, but especially of the Houston communities—that brought me a real sense of gratitude and joy.”

Intuitive Machines was also selected to support the Artemis II mission using its Space Data Network and ground station infrastructure. The company monitored radio signals sent from the Orion spacecraft and used Doppler measurements to help determine the spacecraft's precise position and speed.

Tim Crain, Chief Technology Officer at Intuitive Machines, wrote about the experience last week.

"I specialized in orbital mechanics and deep space navigation in graduate school,” Crain shared. “But seeing the theory behind tracking spacecraft come to life as they thread through planetary gravity fields on ultra-precise trajectories still seems like magic."

UH breakthrough moves superconductivity closer to real-world use

Energy Breakthrough

University of Houston researchers have set a new benchmark in the field of superconductivity.

Researchers from the UH physics department and the Texas Center for Superconductivity (TcSUH) have broken the transition temperature record for superconductivity at ambient pressure. The accomplishment could lead to more efficient ways to generate, transmit and store energy, which researchers believe could improve power grids, medical technologies and energy systems by enabling electricity to flow without resistance, according to a release from UH.

To break the record, UH researchers achieved a transition temperature 151 Kelvin, which is the highest ever recorded at ambient pressure since the discovery of superconductivity in 1911.

The transition temperature represents the point just before a material becomes superconducting, where electricity can flow through it without resistance. Scientists have been working for decades to push transition temperature closer to room temperature, which would make superconducting technologies more practical and affordable.

Currently, most superconductors must be cooled to extremely low temperatures, making them more expensive and difficult to operate.

UH physicists Ching-Wu Chu and Liangzi Deng published the research in the Proceedings of the National Academy of Sciences earlier this month. It was funded by Intellectual Ventures and the state of Texas via TcSUH and other foundations. Chu, founding director and chief scientist at TcSUH, previously made the breakthrough discovery that the material YBCO reaches superconductivity at minus 93 K in 1987. This helped begin a global competition to develop high-temperature superconductors.

“Transmitting electricity in the grid loses about 8% of the electricity,” Chu, who’s also a professor of physics at UH and the paper’s senior author, said in a news release. “If we conserve that energy, that’s billions of dollars of savings and it also saves us lots of effort and reduces environmental impacts.”

Chu and his team used a technique known as pressure quenching, which has been adapted from techniques used to create diamonds. With pressure quenching, researchers first apply intense pressure to the material to enhance its superconducting properties and raise its transition temperature.

Next, researchers are targeting ambient-pressure, room-temperature superconductivity of around 300 K. In a companion PNAS paper, Chu and Deng point to pressure quenching as a promising approach to help bridge the gap between current results and that goal.

“Room-temperature superconductivity has been seen as a ‘holy grail’ by scientists for over a century,” Rohit Prasankumar, director of superconductivity research at Intellectual Ventures, said in the release. “The UH team’s result shows that this goal is closer than ever before. However, the distance between the new record set in this study and room temperature is still about 140 C. Closing this gap will require concerted, intentional efforts by the broader scientific community, including materials scientists, chemists, and engineers, as well as physicists.”

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This article originally appeared on EnergyCapitalHTX.com.