A deep understanding of active site architectures during surface-catalyzed reactions is a crucial step for the design of recyclable heterogeneous catalysts for organic synthesis. In this work, a droplet-based microfluidic setup was developed and applied to perform Suzuki-Miyaura coupling over heterogenous single-atom Pd-catalyst. The catalyst suspensions were confined inside the droplets of about 10 nanoliters acting as nanoreactors, each containing only few nanograms of Pd. In situ Pd K- and L3-edges X-ray absorption spectroscopy studies of the active catalytic sites were conducted at SuperXAS and Phoenix beamlines at PSI, providing insights into the evolution of the Pd local surrounding and electronic structure under reaction conditions. We confirmed a surface-catalyzed mechanism, revealing the distinct electronic structure of active Pd centers compared to homogeneous systems, and highlighting the stabilizing role of ligands and bases. The project is done in collaboration with Prof. Javier Pérez-Ramírez and Prof. Andrew DeMello groups at ETH Zurich.
Contact
Dr Aram Bugaev
Operando spectroscopy group
Swiss Light Source, Paul Scherrer Institute
5232 Villigen-PSI, Switzerland
Telephone: +41 56 310 32 53
E-mail: aram.bugaev@psi.ch
Original Publication
Droplet-Based Microfluidics Reveals Insights into Cross-Coupling Mechanisms over Single-Atom Heterogeneous Catalysts
Thomas Moragues, Dr. Georgios Giannakakis, Andrea Ruiz-Ferrando, Dr. Camelia N. Borca, Dr. Thomas Huthwelker, Dr. Aram Bugaev, Prof. Andrew J. de Mello*, Prof. Javier Pérez-Ramírez*, Dr. Sharon Mitchell*
Angewandte Chemie Int. Ed. , 12 March 2024
DOI:110.1002/anie.202401056