Study of cooperativity between cobalt single atoms and nanoparticles during catalytic selective hydrogenation

Work package:
The ultimate dispersion that can be achieved for a supported catalyst is when the metal atoms are all isolated from each other. When these metallic single atoms (SAs) are stabilized only by the support (absence of organic ligands) one can speak of supported metal single atom catalysts .[1] Metal single atoms (SAs) have coexisted with metal nanoparticles (NPs) for a long time in supported catalysts,[2] and may have played significant roles in many catalytic processes, but they have rarely been recognized as active sites. For hydrogenation reactions, where the active phase should activate dihydrogen, the cationic character of SAs makes them less active than NPs. However, it was recently reported that cooperative catalysis can operate between SAs and NPs for some hydrogenation reactions.[3] During this internship we intend: i) to produce carbon-supported catalysts containing only cobalt SAs (CoSA), only cobalt NPs (CoNP) produced by chimie douce,[4] and various mixtures of CoSA and CoNP, ii) to characterize them using various methods (STEM-HAADF, XPS), and iii) to study their reactivity for selective hydrogenation reactions. The ultimate goal of this internship is to try to draw structure/performance correlations.