Speakers and abstracts

Université Grenoble Alpes, Saint-Martin-d'Hères

marie-noelle.collomb@univ-grenoble-alpes.fr

Marie-Noëlle Collomb is Director of Research at the Centre National de la Recherche Scientifique (CNRS) in Grenoble (France) and leader of the group “Artificial Photosynthesis and Energy Vectors” in the Chimie Inorganique Rédox laboratory of the Département de Chimie Moléculaire at the University Grenoble Alpes (UGA). She obtained her Master degree in electrochemistry in 1990 from the Institut Polytechnique of Grenoble and her PhD in chemistry in 1993 from the UGA working on the electrocatalytic carbon dioxide reduction with molecular complexes under the mentorship of Alain Deronzier. After a year postdoctoral fellowship with Prof. Marc Fontecave at UGA, she joined the CNRS in 1994 as research scientist and was promoted Director of Research in 2007. In 1998-1999, she was CNRS research associate in the groups of Professors Robert H. Crabtree and Gary W. Brudvig at Yale University (New Haven, USA) (NATO fellowship), working on manganese chemistry. She has published over 105 papers in peer-reviewed journal. Her research interests include molecular and hybrid systems for photocatalytic hydrogen production, nanostructured hydrid (photo)electrode materials for (photo)electrocatalytic water oxidation and reduction, as well as the design of new molecular water reduction catalysts and photosensitizers.

Title: Photo-induced redox catalysis for hydrogen production with molecular and hybrid systems

The conversion of solar energy into fuel molecules, such as dihydrogen by light-driven water splitting, is the subject of considerable interest as it constitutes a sustainable and carbon neutral way to face current energy challenges. A largely investigated approach to reduce protons into H₂, relies on molecular photocatalytic systems in homogeneous solution. A chromophore, or “photosensitizer” (PS), absorbs light energy and transfers electrons to the catalyst, which activates the chemical reaction. In such systems, a sacrificial electron donor (SD) acts as the primary source of electrons. This talk will present our efficient molecular systems for the visible-light-driven H₂ production in water using rhodium and cobalt molecular catalysts and the ruthenium tris-bipyridine as photosensitizer. We also recently explore promising alternatives to rare and expensive metal based photosensitizers and demonstrate the great potential of a water soluble triazatriangulenium organic dye as well as of semiconductor nanocrystals (quantum dots) free of toxic cadmium, CuInS₂/ZnS as efficient and robust visible-light-absorbing PSs for H₂ production when associated with a molecular cobalt catalyst.

Department of Chemistry and Pharmacy, Friedrich Alexander University, Erlangen, Germany

joerg.libuda@fau.de

Jörg Libuda studied Chemistry and received his Ph.D. from the Ruhr-Universität Bochum (1996), Germany, before he became workgroup leader at the Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany. He was postdoctoral researcher at Princeton University (New Jersey, USA) and received his habilitation from the Humboldt-Universität zu Berlin, Germany. In 2005 became Professor of Physical Chemistry at the University of Erlangen-Nuremberg, Germany. Since 2019 he is Full Professor of Interface Research and Catalysis and Head of the Erlangen Catalysis Resource Center at the same University. The Libuda Group is recognized for its pioneering work in the field of kinetics and dynamics of chemical processes at complex interfaces bridging between fundamental sciences, engineering and industrial research. The Group’s mission is to provide better mechanistic understanding of the interface chemistry for emerging applications in heterogeneous catalysis, electrocatalysis, energy conversion, hydrogen storage, photochemistry, and molecular electronics. The Group’s strategy aims at developing model interfaces starting from a surface science approach and investigating their functionalities from ultrahigh vacuum conditions to realistic environments. This includes in-situ and operando studies in reactive gases, liquids or at electrified interfaces. The range of model materials comprises metals, oxides, alloys, hybrid and nanomaterials, ionic liquids, and organic films.

Title: Model interfaces in catalysis and energy science: From surface science to electrochemistry and photoelectrochemistry

Designing complex interfaces is the key to the development of new functional materials in energy technology and energy-related catalysis. In our work, we explore model systems, which provide detailed insight into the chemistry and physics at such functional interfaces. Complex, yet atomically-defined model systems are studied both under ‘ideal’ surface science conditions and under ‘real’ conditions, i.e. in contact with gases, liquids, in electrochemical, and in photoelectrochemical environments. The approach is illustrated showing examples from our recent research.[1-4] First, we investigate model systems for complex oxide-based electrocatalysts. We describe how such model electrodes are prepared and characterized by surface science methods in ultrahigh vacuum and, subsequently, are studied in liquid electro­lytes preserving their atomic structure. We investigate the role of particle size effects and identify the origin of metal‒support interactions. In the second example, we scrutinize organic-oxide hybrid interfaces. Here, functional organic layers are anchored to atomi­cally-defined oxide surfaces using specific linker groups, e.g. carboxylates or phosphonates. We investigate the anchoring mecha­nism and show that binding motifs, molecular orientation, and stability are controlled by the structure of the surface. Combining surface science and electrochemical studies, we identify the role of the charged interface in the anchoring reaction. Finally, we investigate molecular systems for solar energy storage. Scrutinizing norbor­nadiene-based photoswitches, we show that such molecules can be anchored to surfaces and photochemically converted under surface science conditions and at the solid-liquid interface. Both thermally and electrochemically triggered back-conversion is possible with high reversibility.

Department of Chemistry, University of Cambridge, Cambridge, UK
er376@cam.ac.uk

Erwin Reisner received his education and professional training at the University of Vienna (PhD in 2005 and Habilitation in 2010), the Massachusetts Institute of Technology (postdoc from 2005-2007) and the University of Oxford (postdoc from 2008-2009). He joined the University of Cambridge as a University Lecturer in the Department of Chemistry and as a Fellow of St. John’s College in 2010. He became the head of the Christian Doppler Laboratory for Sustainable SynGas Chemistry in 2012, was appointed to Reader in 2015, and his current position as Professor of Energy and Sustainability in 2017. His laboratory explores chemical biology, synthetic chemistry, materials science, and engineering relevant to the development of solar-driven processes for the sustainable synthesis of fuels and chemicals. He acts as the Principal Investigator of the Cambridge Centre for Circular Economy Approaches to Eliminate Plastic Waste and director of the UK Solar Fuels Network, where he promotes and coordinates the national activities in artificial photosynthesis.

Title: Interfacing nature’s catalytic machinery with synthetic materials for semi-artificial photosynthesis

Semi-artificial photosynthesis interfaces biological catalysts with synthetic materials and aims to overcome the limitations of natural and artificial photosynthesis. It also provides an underexplored strategy to study the functionality of biological catalysts on synthetic scaffolds through a range of techniques. This presentation will summarise our progress in integrating biocatalysts in bespoke hierarchical 3D electrode scaffolds and photoelectrochemical circuits. We will first discuss the fundamental insights gained into the function of the water oxidation Photosystem II, where (i) unnatural charge transfer pathways have been revealed at the enzyme-electrode interface, and (ii) O₂ reduction that short-circuit the water-oxidation process has been discovered. The wiring of Photosystem II to a H₂ evolving hydrogenase or a CO₂ reducing formate dehydrogenase has subsequently enabled the in vitro re-engineering of natural photosynthetic pathways. We have assembled efficient H₂ evolution and CO₂ reduction systems that are driven by enzymatic water oxidation using semi-artificial Z-scheme architectures. In contrast to natural photosynthesis, these photoelectrochemical cells allow panchromic light absorption by using complementary biotic and abiotic light absorbers. As opposed to low-yielding metabolic pathways, the electrochemical circuit provides effective electronic communication without losses to competing side-reactions. Progress in the integration of robust live cyanobacteria in 3D structured electrodes will also be discussed.

Prof. Mårten Ahlquist

KTH Royal Institute of Technology, Stockolm, Sweden

ahlqui@kth.se

Marten Ahlquist is currently Associate Professor and pro-prefect at the Department of Theoretical Chemistry & Biology at KTH Royal Institute of Technology in Stockholm Sweden. His work is focused on modelling of molecular catalysts, mainly for activation of strong bonds and small molecules, including C-H activation, water oxidation, electrochemical catalysis, CO2 activation, and H2 production. After his M.Sc. in 2004 at Lund University Sweden he moved to the Technical University of Denmark for his doctoral studies. He received his Ph.Din 2007 for his work on palladium and copper catalyzed reactions involving alkynes. This work was supervised by Per-Ola Norrby in collaboration with experimental groups, including Nobel Laureate K. Barry Sharpless. In 2007 he began his postdoctoral studies at Caltech under the supervision of William A. Goddard III. The direction was still on metal catalyzed reactions, but now under more extreme conditions. The focus was on mechanistic studies of platinum catalyzed methane to methanol oxidation in fuming sulfuric acid. In 2009 he returned to Sweden and started his independent career at KTH in Stockholm. His current research is directed towards understanding molecular catalysts in complex and realistic environments.

Title: Simulating molecular catalysts at interfaces and in explicit solvent

Designing complex interfaces is the key to the development of new functional materials in energy technology and energy-related catalysis. In our work, we explore model systems, which provide detailed insight into the chemistry and physics at such functional interfaces. Complex, yet atomically-defined model systems are studied both under ‘ideal’ surface science conditions and under ‘real’ conditions, i.e. in contact with gases, liquids, in electrochemical, and in photoelectrochemical environments. The approach is illustrated showing examples from our recent research.[1-4] First, we investigate model systems for complex oxide-based electrocatalysts. We describe how such model electrodes are prepared and characterized by surface science methods in ultrahigh vacuum and, subsequently, are studied in liquid electro­lytes preserving their atomic structure. We investigate the role of particle size effects and identify the origin of metal‒support interactions. In the second example, we scrutinize organic-oxide hybrid interfaces. Here, functional organic layers are anchored to atomi­cally-defined oxide surfaces using specific linker groups, e.g. carboxylates or phosphonates. We investigate the anchoring mecha­nism and show that binding motifs, molecular orientation, and stability are controlled by the structure of the surface. Combining surface science and electrochemical studies, we identify the role of the charged interface in the anchoring reaction. Finally, we investigate molecular systems for solar energy storage. Scrutinizing norbor­nadiene-based photoswitches, we show that such molecules can be anchored to surfaces and photochemically converted under surface science conditions and at the solid-liquid interface. Both thermally and electrochemically triggered back-conversion is possible with high reversibility.

Dr. Etsuko Fujita

Brookhaven National Laboratory, Upton, NY, USA
fujita@bnl.gov

Etsuko Fujita is a tenured Senior Chemist and leader of the Artificial Photosynthesis group in the Chemistry Division at Brookhaven National Laboratory (BNL). She is the recipient of the 2008 BNL Science and Technology Award for outstanding research in solar fuels generation. She received a B.S. in Chemistry from Ochanomizu University, Tokyo and a Ph.D. in Chemistry from the Georgia Institute of Technology. Her major research interest is solar fuels generation from water and carbon dioxide via mechanistic and kinetic investigations. She also conducts studies of photochemistry of transition metal complexes; CO2 hydrogenation and formic acid dehydrogenation in aqueous solutions using Cp*Ir complexes bearing bio-inspired ligands, and earth-abundant heterogeneous catalysts for electrochemical hydrogen evolution reactions. She has been a member of several advisory boards of institutions involved in conducting solar energy research and served as a co-guest editor for special issues of journals for small molecule activation and solar fuel generation.

Title: CO₂ reduction and hydrogenation using metal complexes with pyridinol-type ligands

The concentration of CO₂ in the atmosphere has reached unprecedented levels and continues to increase owing to an escalating rate of fossil fuel combustion, causing concern about climate change and rising sea levels. In view of the inevitable depletion of fossil fuels, it is important to pursue the recycling of carbon dioxide to fuels and chemicals. Carbon dioxide utilization under mild conditions can be achieved with: (i) so-called artificial photosynthesis using photoinduced electrons; (ii) bulk electrolysis using electricity produced by photovoltaics; and (iii) CO₂ hydrogenation using solar-produced H₂. At this meeting, we will present our research on CO₂ reduction and hydrogenation using molecular catalysts focusing on catalysts bearing pyridinol-type ligands that provide second coordination-sphere effects.

The work carried out at Brookhaven National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under contract DE-SC0012704.

Prof. Tanja Cuk

University of Colorado at Boulder, Boulder, CO, USA

tanja.cuk@colorado.edu

Dr. Cuk obtained her Ph.D. in Applied Physics at Stanford University in 2007 and completed a Miller Postdoctoral fellowship at the University of California, Berkeley in 2010. She is currently an Associate Professor of Chemistry at the University of Colorado, Boulder, Faculty Fellow at the Renewable and Sustainable Energy Institute (RASEI), and Adjunct Professor at the National Renewable Energy Laboratory (NREL). Her research focuses on the fundamental mechanisms involved in converting an electric current into a storable fuel at solid-liquid (electrode-electrolyte) interfaces. To do this, she utilizes multiple time-resolved spectroscopies to probe catalytic reactions at surfaces and collaborates with theorists on the experimental observables. She currently serves on the scientific advisory board of the ARC CBBC Consortium for a Sustainable Future in the Netherlands. She is also a council member of the United States Department of Energy Chemical Sciences, Geosciences, & Biosciences Division.

Title: Resolving chemical bond dynamics at an electrode surface

Catalytic mechanisms at electrode surfaces guide the development of electrochemically-controlled energy storing reactions and chemical synthesis. The intermediate steps of these mechanisms are challenging to identify in real time, but are critical to understanding the speed, stability, and selectivity of product evolution.  In my group, we employ photo-triggered vibrational and electronic spectroscopy to time-resolve the catalytic cycle at a surface, identifying meta-stable intermediates and critical transition states which connect one to another.  The talk will focus on the highly selective water oxidation reaction at the semiconductor (SrTiO₃)-aqueous interface, triggered by an ultrafast light pulse in an electrochemical cell.  Here, I will describe the dynamics from the birth of the initial intermediates that trap charge (Ti-O^· and Ti-O^·-Ti) through the next event, suggested to be the formation of the first O-O bond of O₂ evolution.  The dynamics of charge screening at the interface, a hallmark of electrochemically controlled reactions, will be addressed in both aqueous and non-aqueous (battery) electrolytes.  While many open questions remain, these experiments provide and benchmark the opportunity to quantify intermediates at an electrode surface and their associated dynamics.