Time: 23th March, 2018, 2:00-3:30 pm
Venue: Room 201, Basic Energy Science Buidling
Lecturer：Dávid F. Srankó, Research fellow - MTA Centre for Energy Research
Recent years with the expanding importance of renewable energy, significant attention turned to the energy conversion, e.g., converting electrical to chemical energy. The electrochemical reduction of CO2 is one of the most promising way for the near future, because it offers the possibility to produce industrially valuable commodity chemicals while recycling CO2 can complete the anthropogenic carbon cycle.
Although gold and silver are the most active catalysts for the electrochemical reduction of CO2 to CO, copper has the unique ability for the production of hydrocarbons. There are several examples for improving the catalytic efficiency, e.g., alloying with another metal, or enhancing the number of catalytic sites enlarging the surface roughness by electrochemical or thermal modification. The efficacy is limited by the amount of CO in the reaction. Coupling copper with silver can have a favorable effect on the ratio of the produced CO, therefore increasing the amount of C2 products.
On the other side of the electric cell, increasing the efficiency of the oxidative half-reaction [oxygen evolution reaction (OER); 2H2O → O2 + 4H+ + 4e (in acid); 4OH → 2H2O + O2 4e (in base)], - in which the release of O2 involves an overall four-electron/four-proton process with the final formation of an oxygen oxygen bond - is currently one of the most challenging goals in catalysis.
As an electrocatalyst, more attention has been focused on the Ni(II)-Fe(III) LDH that is the active species of the Fe containing Ni-based oxygen evolution catalyst (OEC) or Ni Feoxyhydroxide ((Ni(Fe)OOH), which is so far the most active OER electrocatalyst under basic conditions. In the brucite-like structure the Fe(III) can easily substitute for the Ni(II), forming catalytically active, structurally-stabilized Fe sites. Previous findings have conclusively demonstrated the beneficial role of Fe in the catalytic activity of pure NiOOH. Moreover, Fe(III) has been identified as the catalytically active site. One possible reason is the distorted octahedral structure, where the different Fe-O bond lengths seem to indicate that the local bond structure around the metal centers plays a crucial role in the activity. In summary, the Ni-Fe-oxyhydroxide has high catalytic activity in OER and the Ni(II)Fe(III)-LDH phase is critical for this activity, although many questions remain about the effect of local atomic structure on catalytic activity.
David F. Sranko (Hungary) is presently a research fellow at the Department of Surface Chemistry and Catalysis, at the MTA Centre for Energy Research in Hungary.
He completed his Master thesis at University of Szeged, Szeged, Hungary, as an environmentalist. Holds PhD since 2008 from the same University.
His scientific career has been in inorganic chemistry and material sciences, synthesis of layered double hydroxides and their application in 2+2 topotactic photodimerization of cinnamic acid derivatives, synthesis of photosensitized iron based OER catalysts and CO2 electrochemical reduction. In 2016 he has spent 1 year at the Joint Center for Artificial Photosynthesis in Berkeley as a postdoctoral scholar working in the research group of Alexis T. Bell.
Contact: GE Rile, DNL2005