A research team from the Institute of Metal Research (IMR) of the Chinese Academy of Sciences has developed an efficient, stable, atomic-scale catalyst for carbon monoxide (CO) oxidation. This advance offers promising strategies for environmental catalysis and designing low-cost, high-performance catalysts.

The study, published as a cover article in Nano-Micro Letters on January 5, addresses a long-standing challenge in catalysis. 

Although single-atom catalysts maximize the use of precious metals, they often struggle to activate multiple reactants, such as CO and oxygen (O₂), simultaneously. To address this issue, the IMR team, led by Profs. LIU Hongyang and SUN Bo in collaboration with Chongqing University, constructed a catalyst featuring atomically dispersed platinum-ruthenium (Pt-Ru) pairs anchored on defective graphene.

Using a straightforward co-impregnation method, the researchers constructed stable Pt-Ru dual-atom active sites. Advanced characterization techniques confirmed the formation of a direct Pt-Ru bond. This bonding interaction enhanced the metallic nature of both atoms, enabling them to work in synergy. 

During the reaction, CO preferentially adsorbs to the Pt atom, while O₂ is effectively activated at the bridging site between the Pt and Ru atoms. This cooperative action overcomes the competitive adsorption limitation of single-atom catalysts and dramatically reduces the energy barrier for the reaction.

The resulting catalyst, designated Pt₁Ru₁/ND@G, exhibits exceptional performance. At a low temperature of 30 °C, it achieves a CO oxidation turnover frequency (TOF) of 17.6 × 10⁻² s⁻¹. This value is ten times higher than that of a comparable platinum single-atom catalyst and surpasses the performance of most previously reported platinum-based catalysts. Furthermore, the catalyst demonstrated stable activity during a 40-hour continuous test at 80 °C, showcasing its durability.

This work provides an efficient synthesis strategy for dual-atom catalysts and offers fundamental insights into their synergistic reaction mechanisms at the atomic level. It opens new avenues for designing next-generation, atomically precise catalysts for critical environmental and energy applications.

Schematic illustration of the CO oxidation reaction catalyzed by Pt₁Ru₁/ND@G. (Image by IMR)