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Structure and reactivity of bimetallic nanocatalysts

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Heterogeneous catalysis is key to many large-scale industrial processes and in fostering a sustainable future. In recent years, bimetallic nanoparticles (BiM NPs) have been of great experimental interests in the field of heterogeneous catalysis. Indeed, alloying of metal atoms at the nanoscale often leads to improved catalytic activity, selectivity or resistance to poisoning as compared to monometallic NPs. However, the capability to design novel and more efficient BiM catalysts is presently hampered by the lack of a clear picture of structure-reactivity relationships, resulting in very poor access to reaction mechanisms. As a result, research and development of BiM catalysts still mainly involves laborious trial-and-error processes.
To understand the interplay between surface structuration and catalytic properties of BiM nanocatalysts, the Me-ANS group develops advance TEM studies to access the structural changes undergone by catalysts during reaction with single atom sensitivity. Our approach combines both ex situ post-mortem TEM and recently, in situ gas TEM using high pressure gas cells with unprecedented access to the structural evolution of BiM catalysts "in action" under pressure/temperature conditions close to that encountered during laboratory catalytic testing (i.e. atmospheric pressure and/or at high temperature). Through close collaboration with French/international experts in the synthesis/testing of BiM nanocatalysts and their modeling, our aim is to determine the origins of the promotional effect of metal alloying in bimetallic systems so as to guide the rational design of more active catalysts in different reactions. Systems studied recently in the group include Pd-Au, Pd-Ir and Cu-Au BiM NPs

Top : Void formation in a CuAu NP under O2 gas flow at room temperature through nanoscale Kirkendall effect. Bottom : Reversible process under H2 gas flow.

Projects :
ANR DINAMIC (2011 - 2014)
ANR TOTEM (2018 - 2021)

Main collaborators :
Laurent Piccolo - Institute of Researches on Catalysis and Environment of Lyon (IRCELYON)
Catherine Louis / Laurent Delannoy - Réactivité de Surface laboratory (Pierre et Marie Curie University).
Hazar Guesmi - Charles Gerhardt Institute, Montpellier
Beien Zhu - Institute of Applied Physics of Shanghai, China

Main Publications :

Selective hydrogenation of butadiene over TiO2 supported copper, gold and gold–copper catalysts prepared by deposition–precipitation
Laurent Delannoy, Gode Thrimurthulu, Padigapati S Reddy, Christophe Méthivier, Jaysen Nelayah, Benjaram M Reddy, Christian Ricolleau, Catherine Louis
Phys. Chem. Chem. Phys. 16 (48), 26514-26527

Long-range chemical orders in Au–Pd nanoparticles revealed by aberration-corrected electron microscopy
J Nelayah, NT Nguyen, D Alloyeau, GY Wang, C Ricolleau
Nanoscale 6 (17), 10423-10430

Nanoalloying bulk-immiscible iridium and palladium inhibits hydride formation and promotes catalytic performances
C Zlotea, F Morfin, TS Nguyen, NT Nguyen, J Nelayah, C Ricolleau, M Latroche, L Piccolo
Nanoscale 6 (17), 9955-9959

Au–Rh and Au–Pd nanocatalysts supported on rutile titania nanorods : structure and chemical stability
Zere Konuspayeva, Pavel Afanasiev, Thanh-Son Nguyen, Luca Di Felice, Franck Morfin, Nhat-Tai Nguyen, Jaysen Nelayah, Christian Ricolleau, Z. Y. Li, Jun Yuan, Gilles Berhault and Laurent Piccolo
Phys. Chem. Chem. Phys., 2015, Advance Article
DOI : 10.1039/C5CP00249D

New insights into the mixing of gold and copper in a nanoparticle from a structural study of Au–Cu nanoalloys synthesized via a wet chemistry method and pulsed laser deposition
Hélène Prunier, Jaysen Nelayah, Christian Ricolleau, Guillaume Wang, Sophie Nowak, Anne-Félicie Lamic-Humblot and Damien Alloyeau
Phys. Chem. Chem. Phys., 2015, Advance Article
DOI : 10.1039/C5CP01491C