Converting carbon dioxide into useful fuels and chemicals at industrial scale requires overcoming a fundamental chemical challenge: the CO₂ molecule is extremely stable, and breaking its carbon-oxygen bonds demands energy. High-temperature electrolysis, running the reaction at 800°C in a solid oxide cell, has long offered a theoretical path to efficiency, but the catalysts that accelerate the reaction tend to break down under such extreme conditions.
A team from the Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences, has now demonstrated a way to keep the catalyst stable: anchoring individual iridium atoms onto a perovskite cathode, where they remain atomically dispersed even at 800°C. The result, published in Nature Communications on July 18, is a current density of 3.02 amps per square centimeter, among the highest ever reported for CO₂ electrolysis, sustained for over 600 hours without degradation.
How It Works
The device is a solid oxide electrolysis cell (SOEC), which uses a ceramic electrolyte that conducts oxygen ions at high temperature. On the cathode side, CO₂ is split into CO and O²⁻ ions; the ions travel through the electrolyte to the anode, where they recombine into oxygen gas. The overall reaction is CO₂ → CO + ½O₂.
The cathode material is a perovskite, lanthanum strontium iron oxide (La₀.₆Sr₀.₄FeO₃₋δ, or LSF), decorated with individual iridium atoms. The key breakthrough is an in situ strong metal-support interaction (SMSI) that forms during cell fabrication and operation. This interaction does two things simultaneously: it locks the iridium atoms in place, preventing the atomic migration and clustering that normally kills single-atom catalysts at high temperature, and it alters the electronic structure of the perovskite surface to promote the formation of oxygen vacancies, the active sites where CO₂ molecules bind and react.
The Numbers
Compared with pristine LSF, the iridium-decorated cathode boosted current density by 80.8%, from 1.67 to 3.02 A/cm² at 1.5 V and 800°C. The faradaic efficiency, the fraction of electrons that go to the desired CO product rather than side reactions, was near 100%. The cell ran for more than 600 hours with no measurable degradation.
For context, state-of-the-art SOEC cathodes typically achieve 1.0 to 2.5 A/cm² under similar conditions. The 3.02 A/cm² result, combined with exceptional stability, places this catalyst at the frontier of high-temperature CO₂ electrolysis performance.
Why High Temperature Matters
Low-temperature CO₂ electrolysis, operating near room temperature, typically achieves 100–500 mA/cm² and struggles with competing hydrogen evolution and CO₂ solubility limits. At 800°C, several things change: the reaction kinetics accelerate exponentially, the thermodynamic voltage required decreases (meaning some energy can come from cheap heat rather than expensive electricity), and the ceramic electrolyte’s ionic conductivity rises dramatically. The result is a system that can process CO₂ at far higher rates and with near-perfect selectivity to CO.
The output, high-purity carbon monoxide, is a valuable industrial feedstock that can be combined with green hydrogen to produce synthetic jet fuel, methanol, or other hydrocarbons, creating a path to carbon-neutral fuels if the electricity comes from renewable sources.
Caveats
Iridium is a precious metal at roughly $150–200 per gram. Even at single-atom loading levels, the economics of scale-up depend on keeping iridium content extremely low. The 600-hour stability test was performed on a single laboratory cell, not a full stack, and real industrial devices require 10,000–40,000 hours of reliable operation. The 800°C operating temperature also demands expensive materials for seals, interconnects, and thermal management.
The paper has been accepted and published as an early-access manuscript in Nature Communications (DOI: 10.1038/s41467-026-75580-x) by S. Zhang, S. Wang, Y. Song, G. Wang, X. Bao, and colleagues.
Sources
1. S. Zhang, S. Wang, H. Liu et al., “Stable high-valent iridium single atoms for high-temperature CO₂ electrolysis,” Nature Communications (2026). DOI: 10.1038/s41467-026-75580-x