When single atoms aggregate at the benefit of catalysis

Single atoms hardly enjoy their isolated state, especially on weakly interacting supports. Operando experiments and DFT calculations reveal that, whereas single Pt atoms are stabilized on g-alumina under oxidizing atmosphere thanks to Pt-O_ads-Al_supp bridges, they are prone to clustering under reducing atmospheres. However, the resulting subnanometric Pt clusters appear much more active in CO oxidation than their single-atom counterparts.

Dynamics of single Pt atoms on alumina during CO oxidation monitored by operando X-ray and infrared spectroscopies C. Dessal, T. Len, F. Morfin, J.L. Rousset, M. Aouine, P. Afanasiev, L. Piccolo ACS Catal. 2019, 9, 5752

Atmosphere-dependent stability and mobility of catalytic Pt single atoms and clusters on g-Al₂O₃ C. Dessal, A. Sangnier, C. Chizallet, C. Dujardin, F. Morfin, J.L. Rousset, M. Aouine, M. Bugnet, P. Afanasiev, L. Piccolo Nanoscale 2019, 11, 6897