We report herein a mononuclear, homogeneous photocatalyst for H2 production with sunlight. The synthesis and characterization of a (pyridyl)-N-heterocyclic carbene tungsten tetracarbonyl complex W(pyNHC)(CO)4 is described, and its application as a precatalyst for photocatalytic generation of H2 is evaluated. Electrochemical and photophysical studies were used to characterize and evaluate the precatalyst and in situ generated catalyst [W(pyNHC)(CO)3] for the visible-light-driven production of H2 in the presence of triflic acid and decamethylferrocene without an additional photosensitizer. Under irradiation with a solar-simulated spectrum, a catalyst turnover number (TON) of >17 in 3 h of reaction time is observed for the production of H2 with this system, which compares favorably to a prior reported (multinuclear) homogeneous photocatalyst using visible light (4 TON). Photonic energy was found to be necessary to access the active catalysts from the precatalyst and in the catalytic cycle. A mechanism is detailed on the basis of a combined photophysical and computational approach.
|Number of pages||10|
|State||Published - Jun 1 2018|
Bibliographical noteFunding Information:
A.J.H., H.S., R.L., S.G., S.A., H.C., K.T., J.J., N.I.H., R.H.S., C.E.W., and J.H.D. thank the NSF for funding (OIA-1539035). T.J. and A.D. thank NSF for funding (CHE-1255519). Computations were performed at the Mississippi State University High Performance Computing Collaboratory and the Mississippi Center for Supercomputing Research. This study was also partly supported by Mississippi State University Office of Research and Economic Development. SG thanks the Louisiana Board of Regents Graduate Fellowship Program for award 020-GF-14.
© 2018 American Chemical Society.
ASJC Scopus subject areas
- Chemistry (all)