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




Duration: NanoX master Internship (8 months part-time in-lab immersion)

Latest starting date: 02/11/2021

Localisation: LPCNO (NCO)
LCC (group C)

Katerina Soulantika, DR-CNRS
Philippe Serp, Prof. Toulouse INP

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.

STEM-HAADF images of nanocatalysts containing: a) metal NPs; b) metal SAs; and c) mixture of metal SAs and NPs.

[1] L. Zhanf, et al., Chem. Rev. 2020, 120, 683–733 [2] U. Petek, et al., Catalyst, 2019, 9, 134. [3] P. Serp, Nanoscale 2021, 13, 5985–6004. [4] N. Liakakos, et al., J. Am. Chem. Soc. 2012, 134, 17922–17931.

Areas of expertise:
Nanoparticle synthesis, Chimie Douce, Single Atom Catalysis, Nanocatalysis, Hydrogenation

Required skills for the internship:
The successful candidate will have a formation in nanomaterial synthesis (manipulation with Schlenck techniques and use of a glovebox) and characterization (TEM, HRTEM, STEM-HAADF, XPS). Training on an electron microscope will be carried out during the internship. Skills in catalysis will also be appreciate.