Chemical and photocatalytic water oxidation by mononuclear Ru catalysts
2013 (English)In: Cuihuà xuébào, ISSN 0253-9837, Vol. 34, no 8, 1489-1495 p.Article in journal (Refereed) Published
Four mononuclear Ru complexes with different substituents on the para position of the pyridine ligand of Ru(bda)(pic)(2) (H(2)bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; pic = picoline) were synthesized and characterized by H-1 nuclear magnetic resonance or X-ray crystallography. The electrochemical properties of this series of compounds in acidic and neutral conditions were studied by cyclic voltammetry. Their catalytic activity towards water oxidation was investigated using a chemical oxidant ([Ce(NH4)(2)(NO3)(6)] (Ce-IV) in acidic solution, or driven by visible light in a three-component system containing a photosensitizer ([Ru(bpy)(3)](2+)) and an electron acceptor (S2O82-). For the chemical water oxidation, complex 1 was found to be the most effective, exhibiting a turnover number (TON) of up to 4000. The pyridine substituent at the 4-position in 1 may be protonated giving an intensive electron-withdrawing effect. Complex 2 bears the most electron-withdrawing trifluoromethyl group under neutral conditions and showed the highest photocatalytic activity with a TON of 270 over 2 h. It was concluded that the more electron-withdrawing substituents led to higher activity towards oxygen evolution for this type of Ru catalysts in the oxidation of water.
Place, publisher, year, edition, pages
2013. Vol. 34, no 8, 1489-1495 p.
Water splitting, Water oxidation, Ruthenium complex, Electron-withdrawing effect, Photocatalysis
IdentifiersURN: urn:nbn:se:kth:diva-128483DOI: 10.1016/S1872-2067(12)60600-7ISI: 000323239600003ScopusID: 2-s2.0-84883297676OAI: oai:DiVA.org:kth-128483DiVA: diva2:648018
FunderSwedish Energy AgencyKnut and Alice Wallenberg Foundation
QC 201309132013-09-132013-09-122013-09-13Bibliographically approved