Mechanistic insights into electrocatalytic CO2 reduction within [Ru-II(tpy)(NN)X](n+) architectures
2014 (English)In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 43, no 40, 15028-15037 p.Article in journal (Refereed) Published
A series of Ru-II-polypyridyl complexes of the design [Ru-II(tpy)(NN)X](n+) (tpy = 2,2':6',2 ''-terpyridine; NN = bidentate polypyridine; X = Cl or CH3CN; n = 1 or 2) have been synthesized and analyzed for their ability to function as electrocatalysts in the reduction of CO2 to CO. Varying the electron-donating/withdrawing character of the NN polypyridyl ligand has allowed for modification of electron density at the formally Ru-II metal center. Complexes where X = Cl- display ligand substitution for CH3CN with differing rates of Cl- dissociation (k(-Cl)), therefore providing a degree of insight into the electron density and thus the chemical activity at the Ru-II center. Detailed analysis of the cyclic voltammograms under argon vs. CO2 atmospheres using multiple switching potentials and scan rates ranging from v = 25-2000 mV s(-1) has painted a picture of how monodentate ligand lability due to NN polypyridyl electron-donating character is related to electrocatalytic CO2 reduction activity of Ru-II-polypyridyl complexes. From these studies, multiple mechanistic pathways towards generating the catalytically active [Ru(tpy(-))(NN-)CO2](0) species are proposed and differ via the order of electrochemical and chemical processes.
Place, publisher, year, edition, pages
2014. Vol. 43, no 40, 15028-15037 p.
IdentifiersURN: urn:nbn:se:uu:diva-236528DOI: 10.1039/c4dt01591fISI: 000343023200015OAI: oai:DiVA.org:uu-236528DiVA: diva2:767217