A Systematic Comparative Study of Hydrogen-Evolving Molecular Catalysts in Aqueous Solutions
2015 (English)In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 8, no 21, p. 3632-3638Article in journal (Refereed) Published
Resource type
Text
Abstract [en]
We describe here a systematic, reliable, and fast screening method that allows the comparison of H-2-forming catalysts that work under aqueous conditions with two readily prepared chemical reductants and two commonly used photosensitizers. This method uses a Clark-type microsensor for H-2 detection and complements previous methods based on rotating disk electrode measurements. The efficiencies of a series of H-2-producing catalysts based on Co, Ni, Fe, and Pt were investigated in aqueous solutions under thermal conditions with europium(II) reductants and under photochemical conditions in the presence of two different photosensitizers {[Ru(bipy)(3)]Cl-2 (bipy=2,2-bipyridine) and eosin-Y} and sacrificial electron donors (ascorbate and triethanolamine, respectively). The majority of catalysts tested were active only under specific conditions. However, our results also demonstrate the impressive versatility of a group of Co catalysts, which were able to produce H-2 under different reducing conditions and at various pH values. In particular, a cobaloxime, [Co(dmgH)(2)(H2O)(2)] (dmgH(2)=dimethylglyoxime), and a cobalt tetraazamacrocyclic complex, {Co(CR)Cl-2}(+) [CR=2,12-dimethyl-3,7,11,17-tetraazabicylo(11.3.1)heptadeca-1(17),2,11,13,15-pentaene], displayed excellent catalytic rates under the studied conditions, and the best rates were observed under thermal conditions.
Place, publisher, year, edition, pages
2015. Vol. 8, no 21, p. 3632-3638
Keywords [en]
analytical methods, electrochemistry, homogeneous catalysis, hydrogen evolution reaction, photochemistry
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-268779DOI: 10.1002/cssc.201501002ISI: 000364525800013PubMedID: 26383700OAI: oai:DiVA.org:uu-268779DiVA, id: diva2:882462
Funder
Swedish Research Council Formas, 213-2014-880Swedish Research Council, 621-2014-5670Magnus Bergvall Foundation2015-12-152015-12-092017-12-01Bibliographically approved