Single-atom catalysis (SAC) is one of the most active frontiers in heterogeneous catalysis. The geometric isolation of metal species in SACs not only maximize the atomic utilization efficiency, but also endow SACs with unique selectivity in various transformations.

The coordination environment of isolated metal atoms in SACs determines the catalytic performance. However, it remains challenge to modulate the coordinative structure while still maintain the single-atom dispersion.

Recently, a research group led by Prof. ZHANG Tao and Prof. WANG Aiqin from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences fabricated a Ru₁/NC SAC with good catalytic activity, selectivity and stability in reductive amination of biomass derived aldehydes/ketones to produce primary amines, and elucidated the structure-performance relationships from the atomic/molecular level.

This study was published in Nature Communications on June 2.

Highly selective and robust single-atom catalyst R₁/NC for reductive amination of aldehydes/ketones (Image by QI Haifeng)

The researchers prepared Ru₁/NC SAC towards the target reaction, and discovered both of catalytic activity and selectivity increases with the decrease of Ru-N coordination numbers. Particularly, Ru₁/NC SAC with Ru₁-N₃ moiety stood out to give the best catalytic performances, which was much superior to the ever reported nanoparticulate and homogeneous Ru catalysts.

Moreover, Ru₁/NC presented excellent durability against poisoning by CO or sulfur-containing compounds, and the single-atom dispersion was well maintained even after reduction under extreme conditions.

This work was supported by the National Key Projects for Fundamental Research and Development of China, the National Natural Science Foundation of China, the Strategic Priority Research Program of the CAS. (Text by QI Haifeng)