We are involved in the three following research themes:

• Operando X-ray spectroscopy of electrocatalytic reactions

• Electronic structure of biomimetic and bioinspired molecular systems

• Microfluidic and electochemical instrumentation

Operando X-ray spectroscopy of electrocatalytic reactions

Since more than a decade, we have been interested in the study of electrocatalytic systems based on transition metal oxides or sulfides, as well as molecular complexes. These systems are active for the oxygen (OER) and hydrogen (HER) evolving reactions, as well as the CO2 reduction reaction (CO2RR). X-ray absorption spectroscopy is our main tool to understand the local and electronic structure of these catalysts and follow their evolution under operating conditions.


Selected publications

Multiple C–C bond formation upon electrocatalytic reduction of CO2 by an iron-based molecular macrocycle

Si-Thanh Dong, Chen Xu and Benedikt Lassalle-Kaiser.*

Chemical Science, 2023, 14, 550-556.

Experimental Evidence of the Role of Short-Range Order on the Electrochemical Activity of Iridium Oxides

M. Elmaalouf, M. Odziomek, S. Duran, M. Gayrard, M. Bari, C. Tard, C. Boissière, A. Zitolo, B. Lassalle-Kaiser, J-Y. Piquemal, O. Ersen, C. Sanchez, M. Giraud, M. Faustini* and J. Peron.*

Nature Communications, 2021, 12, 1, 3935.

Morphological and Structural Evolution of Co3O4 Nanoparticles Revealed by in Situ Electrochemical Transmission Electron Microscopy during Electrocatalytic Water Oxidation

N. Pena, D. Ihiawakrim, M. Han, B. Lassalle-Kaiser, S. Carenco, C. Sanchez, C. Laberty, D. Portehault,* O. Ersen.*

ACS Nano, 2019, 13, 10, 11372-11381.

In Situ Observation of the Formation and Structure of Hydrogen-Evolving Amorphous Cobalt Electrocatalysts

B. Lassalle-Kaiser,* A. Zitolo, E. Fonda, M. Robert, E. Anxolabéhère-Mallart.*

ACS Energy Letters, 2017, 2, 2545-2551.

Structure–Activity Correlations in a Nickel–Borate Oxygen Evolution Catalyst

D. K. Bediako, B. Lassalle-Kaiser, Y. Surendranath, J. Yano, V. K. Yachandra, and D. G. Nocera.*

Journal of the American Chemical Society, 2012, 134, 15, 6801-6809.

Electronic structure of biomimetic and bioinspired molecular systems

We have been interested in synthesizing and characterizing biomimetic molecular complexes that model the Oxygen Evolving Center of Photosystem II for more than a decade, using both electrochemistry and spectroscopy. We are particularly interested in understanding their electronic structure and the distribution of the electronic density between the metal and its ligands. To this end, we use a combination of electrochemistry, UV-Visible, EPR and mostly X-ray spectroscopies. These techniques allow determining the oxidation and spin state, as well as the geometry of the metal of interest. We have studied mononuclear and polynuclear manganese complexes, and more recently Rhodium, Ruthenium and Iron complexes, all relevent to energy-related reactions such as the OER, HER or CO2RR.


Selected publications

In situ X-ray absorption spectroscopy in homogeneous conditions reveals interactions between CO2 and a doubly and triply reduced iron(III) porphyrin, then leading to catalysis

Daniela Mendoza, Si-Thanh Dong, Nikolaos Kostopoulos, Victor Pinty, Orestes Rivada-Wheelaghan, Elodie Anxolabéhère-Mallart,* Marc Robert* and Benedikt Lassalle-Kaiser.*

ChemCatChem, 2022, accepted    

Synthesis and Structural and Electronic Characterization of an Iron Fused Porphyrin

E. A. Reyes Cruz, D. Khusnutdinova, D. Nishiori, B. Lassalle-Kaiser* and Gary F. Moore.*

ChemElectroChem, 2021, 8, 19, 3614-3620.

Isolation of a missing link in the water oxidation reaction

B. Casadevall, V. Martin-Diaconescu, W. R. Browne, S. Fernandez, F. Franco, N. Cabello, J. Benet-Buchholz, B. Lassalle-Kaiser, J. lloret-Fillol.*

Nature Chemistry, 2021, 13, 8, 800+.   

High-spin Mn-oxo complexes and their relevance to the oxygen-evolving complex within PS II

R. Gupta, T. Taguchi, B. Lassalle-Kaiser, E. L. Bominaar, J. Yano, M. P. Hendrich and A. S. Borovik.*

Proceedings of the National Academy of Science of the USA, 2015, 112, 17, 5319-5324.

Activation of a water molecule using a mononuclear Mn complex: from Mn-aquo, to Mn-hydroxo, to Mn-oxyl via charge compensation

B. Lassalle-Kaiser, C. Hureau, D. A. Pantazis, Y. Pushkar, R. Guillot, V. K. Yachandra, J. Yano, F. Neese*, E. Anxolabéhère-Mallart.*

Energy and Environmental Science, 2010, 3, 7, 924-938.


Electrochemical cell design

We develop specific electrochemical cells that allow probing electroactive or catalytic species with X-ray spectroscopy under in situ/operando conditions. These cells can feature heterogeneous or homogeneous systems under static or flowing conditions.

Microfluidics: mixing, sorting, trapping, freezing

We develop microfluidic systems that allow mixing, sorting or trapping (bio)chemical species or biological objects (cells, crystals). Theses systems are combined with synchrotron-base techniques, which are used to probe the structure of these objects under in situ conditions and with time-resolution.


Selected publications

A millisecond passive micromixer with low flow rate, low sample consumption and easy fabrication

Y. Liao, Y. Mechulam and B. Lassalle-Kaiser.*

Scientific Reports, 2021, 11, 1, 201119.

The microfluidic laboratory at Synchrotron SOLEIL

I. Chaussavoine, A. Beauvois, T. Mateo, R. Vasireddi, N. Douri, J. Priam, Y. Liatimi, S. Lefrançois, H. Tabuteau, M. Davranche, D. Vantelon,* T. Bizien,* L. M. G. Chavas,* B. Lassalle-Kaiser.* 

Journal of Synchrotron Radiation, 2020, 27, 1, 230-237.

Time-resolved X-ray absorption spectroelectrochemistry of redox active species in solution

K. Cheaib, B. Maurice, T. Mateo, Z. Halime,* B. Lassalle-Kaiser.*

Journal of Synchrotron Radiation, 2019, 26, 6, 1980-1985.

In Situ/Operando Studies of Electrocatalysts Using Hard X-ray Spectroscopies

B. Lassalle-Kaiser, S. Gul, J. Kern, V. K. Yachandra and J. Yano.*

Journal of electron spectroscopy and related Phenomena, 2017, 221, 18-27