New research article!

Congratulations to Ebrahim Tayyebi, Javed Hussain and Egill Skúlason on their newly published article in Chemical Science!

Why do RuO2 electrodes catalyze electrochemical CO2 reduction to methanol rather than methane or perhaps neither of those?

Abstract

The electrochemical CO2 reduction reaction (CO2RR) on RuO2 and RuO2-based electrodes has been shown experimentally to produce high yields of methanol, formic acid and/or hydrogen while methane formation is not detected. This CO2RR selectivity on RuO2 is in stark contrast to copper metal electrodes that produce methane and hydrogen in the highest yields whereas methanol is only formed in trace amounts. Density functional theory calculations on RuO2(110) where only adsorption free energies of intermediate species are considered, i.e. solvent effects and energy barriers are not included, predict however, that the overpotential and the potential limiting step for both methanol and methane are the same. In this work, we use both ab initio molecular dynamics simulations at room temperature and total energy calculations to improve the model system and methodology by including both explicit solvation effects and calculations of proton–electron transfer energy barriers to elucidate the reaction mechanism towards several CO2RR products: methanol, methane, formic acid, CO and methanediol, as well as for the competing H2 evolution. We observe a significant difference in energy barriers towards methane and methanol, where a substantially larger energy barrier is calculated towards methane formation than towards methanol formation, explaining why methanol has been detected experimentally but not methane. Furthermore, the calculations show why RuO2 also catalyzes the CO2RR towards formic acid and not CO(g) and methanediol, in agreement with experimental results. However, our calculations predict RuO2 to be much more selective towards H2 formation than for the CO2RR at any applied potential. Only when a large overpotential of around −1 V is applied, can both formic acid and methanol be evolved, but low faradaic efficiency is predicted because of the more facile H2 formation

NordCO2 will continue until 2023!!

Time to celebrate!
The progress report for 2019 and the midterm evaluation of NordCO2 has been approved by NordForsk, and the consortium will be funded un til 2023. Congratulations to all NordCO2 members!
We are looking forward to do (and publish) more amazing CO2 science, and would like to thank NordForsk for allowing us to do so 🙂

More about NordForsk at:

New research article from the Skrydstrup Group

Congratulations to Martin B. Johansen, Oliver R. Gedde, Thea S. Mayer and Troels Skrydstrup on their newly published article!

Access to Aryl and Heteroaryl Trifluoromethyl Ketones from Aryl Bromides and Fluorosulfates with Stoichiometric CO

Abstract
We report a sequential one-pot preparation of aromatic trifluoromethyl ketones starting from readily accessible aryl bromides and fluorosulfates, the latter easily prepared from the corresponding phenols. The methodology utilizes low pressure carbon monoxide generated ex situ from COgen to generate Weinreb amides as reactive intermediates that undergo monotrifluoromethylation affording the corresponding aromatic trifluoromethyl ketones (TFMKs) in good yields. The stoichiometric use of CO enables the possibility for accessing 13C-isotopically labeled TFMK by switching to the use of 13COgen.

Read at:

For a list of publications by the members of NordCO2, see our Publications page!

Accepted manuscript from the Hammarström Group

Congratulations to the Leif Hammarström research group at Uppsala University on their ercently accepted manuscript!

From non-innocent to guilty: on the role of redox-active ligand in the electro-assisted reduction of CO2 mediated by a cobalt(II)-polypyridyl complex
N. Queyriaux, K. Abel, J. Fize, J. Pécaut, M. Orio and L. Hammarström
Sustainable Energy & Fuels (2020) accepted 11/5 2020

 Abstract

The electrochemical behavior of [Co(bapbpy)Cl]+ [1-Cl]+, a pentacoordinated polypyridyl cobalt(II) complex containing a redox-active pseudo-macrocyclic ligand (bapbpy: 6,6’-bis-(2-aminopyridyl)-2,2’-bipyridine) has been investigated in DMF. Cyclic voltammograms (CV), recorded in the presence of increasing amounts of chloride anions, highlighted the existence of an equilibrium with the neutral hexacoordinated complex. Under a CO2 atmosphere, CVs of [Co(bapbpy)Cl]+ exhibit significant current enhancement assigned to CO2 catalytic reduction. Controlled-potential electrolysis experiments confirmed formation of CO and HCOOH as the only identifiable products. The addition of water or chloride ions was shown to affect the distribution of the products obtained, as well as the faradaic efficiency associated with their electrocatalytic generation. A combination of electrochemical techniques, chemical reductions, spectroscopic measurements (UV-Vis and IR) and quantum chemical calculations suggests that the ability of the bapbpy ligand to be reduced at moderately negative potentials drastically limits the catalytic performances of [1-Cl]+, by stabilizing the formation of a catalytically-competent CO2-adduct that only slowly reacts with oxide acceptors to evolve towards the desired reduction products.

New issue of Organometallics on CO2 conversion

The latest issue of the journal Organometallics, published just yesterday, is a special issue on CO2 conversion, with our own Assoc. Prof. Kathrin H. Hopmann as editor. Be sure to read the editorial she has written with Prof. N. Iwasawa from the Tokyo Institute of Technology and Prof. N. Hazari from Yale University !
She also designed the cover in collaboration with Dr. J. Darmon from Princeton University.

The article from Marc Obst, Ashot Gevorgyan, Annette Bayer, and Kathrin Hopmann on Copper-Catalyzed Carboxylations is also included in this issue. Congratulations!