Japanese team loads isolated ruthenium atoms densely into carbon, turning CO2 to formic acid

A Tohoku-led team holds up to 11% ruthenium by weight as single atoms, versus under 2% typical, and converts CO2 to formic acid at over 99% selectivity.

Researchers at Tohoku University, working with the University of Tsukuba, Kyoto University and The University of Osaka, have developed a new way to make ruthenium single-atom catalysts. The work, led by Koki Chida and colleagues, appeared in Angewandte Chemie International Edition in 2026.

The method heats a molecularly designed Ru-terpyridine precursor. The result is an ordered, porous carbon framework that holds isolated ruthenium atoms. The precursor molecules are more flexible than those used in earlier methods, so they accommodate the metal atoms better. The catalyst reaches a ruthenium content of up to 11% by weight, while conventional ruthenium single-atom catalysts typically contain under 2%. Associate Professor Takeharu Yoshii of Tohoku's WPI-AIMR notes that atoms usually aggregate at high loadings, and says this method avoids that.

In testing, the catalyst converted carbon dioxide into formic acid with over 99% selectivity. After repeated use it kept its performance, with no sign of metal atoms clumping or of damage to the carbon structure.

Why it matters for abundance: single-atom catalysts use every precious-metal atom as an active site, so packing more of them into a given amount of material could mean fewer resources spent per unit of chemical output. Turning CO2 into a useful chemical is also a route toward cheaper, less wasteful chemical production. That is our reading of the direction, not a result the paper demonstrates.

What to watch: the team plans to try the approach with platinum, palladium and iridium, but that is a plan, not a result. Only CO2-to-formic-acid performance is reported. No cost savings or industrial-scale testing are described, and the number of reuse cycles was not stated.

Source: Phys.org