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Wednesday November 21: Seminar by Marc Robert, Université Paris Diderot

 

"Molecular catalysis of CO2 reduction with Fe and Co complexes - A combined electrochemical and photochemical approach" 


Time: 15:15 

Place: Seminar room, Ångström laboratory House 7, floor 1

Abstract:

Recent attention aroused by the reduction of carbon dioxide has as main objective the production of useful organic compounds and fuels, renewable fuels, in which solar energy would be stored. Molecular catalysts can be employed to reach this goal. One route consists in first converting sunlight energy into electricity that could be further used to reduce CO2 electrochemically. Another approach is to directly use the visible photons and photo-stimulate the electrochemical reduction of the gas in the presence of an appropriate sensitizer and a sacrificial electron donor. Molecular catalysts may provide excellent selectivity but usually with less durability and more complex processability than solid materials. Hybrid systems in which a robust molecular catalyst is associated to a porous carbon material as conductive support may combine the advantages of both homogeneous and heterogeneous catalysis.Using Fe and Co complexes (porphyrins and quaterpyridines), our recent results will be discussed, illustrating the synergy between electrochemical and photochemical approaches and the rich potential of molecular catalysts to generate fuels from CO2 used as a renewable feedstock.

Previous news and events


The First European Congress on Photosynthesis Research was a success!

Over 400 delegates from Europe, and all over the world, discussed recent findings in natural and artificial photosynthesison June 25 - 28, 2018. To see what it was all about, go to the conference homepage: ePS1.org

One of our prominent invited speakers, Junko Yano from Lawrence Berkeley National Laboratory, was interviewed in Swedish national radio. You can listen to the program here (mostly in Swedish).


The CAP workshop 2018

Our annual workshop was held at Sigtunahöjden in Sigtuna, on April 26-27. Thanks for all the interesting presentations everyone, you made the workshop great!

Participants on the CAP workshop in Sigtuna, basking in the April sun.

An osprey was seen flying past the workshop venue.



Previous seminars

Wednesday June 20, 2018, a talk was given by Wolfgang Lubitz, Max-Planck-Insttute of chemical energy conversion, Mülheim, Germany.Title: "Structure and function of [NiFe] hydrogenases probed by spectroscopic and electrochemical techniques."Abstract: Hydrogenases catalyze the reversible heterolytic splitting of H2 at binuclear (NiFe or FeFe) metal centers. Understanding how these enzymes achieve their highg efficiencies is key to developing molecular catalysts for H2 conversion and production. To shed light on the catalytic cycles of these enzymes, intermedates are trapped and characterized by electrochemical and spectroscopic methods, using mostly vibrational spectroscopy and magnetic resonance techniques. The obtained parameters are verified by DFT calculations. The [NiFe] hydrogenases are quite well understood; important results are briefly reviewed. The field of [FeFe] hydrogenases has recently been revolutionized by the discovery of artificial maturation. The focus of this lecture will therefore be on these enzymes.


Wednesday May 16, 2018, a talk was given by Yogi Surendranath, Paul M. Cook Career Development Assistant Professor, Department of Chemistry, MIT

Title: "Bridging Molecular and Heterogeneous Electrocatalysis Through Graphite Conjugation"

Abstract: The efficient interconversion of electrical and chemical energy requires catalysts capable of accelerating complex multi-electron reactions at electrified interfaces. These reactions can be carried out at the metallic surface sites of heterogeneous electrocatalysts or via redox mediation at molecular electrocatalysts. Molecular catalysts yield readily to synthetic alteration of their redox properties and secondary coordination sphere, permitting systematic tuning of their activity and selectivity. Similar control is difficult to achieve with heterogeneous electrocatalysts because they typically exhibit a distribution of active site geometries and local electronic structures, which are recalcitrant to molecular-level synthetic modification. However, metallic heterogeneous electrocatalysts benefit from a continuum of electronic states which distribute the redox burden of a multi-electron transformation, enabling more efficient catalysis. We have developed a simple synthetic strategy for conjugating well-defined molecular catalyst active sites with the extended states of graphitic solids. Electrochemical and spectroscopic data indicate that these graphite-conjugated catalysts do not behave like their molecular analogues, but rather as metallic active sites with molecular definition, providing a unique bridge between the traditionally disparate fields of molecular and heterogeneous electrocatalysis.



Last updated October 29, 2018