title: Photocatalytic Formic Acid Conversion on CdS Nanocrystals with Controllable Selectivity for H2 or CO.
abstract: Formic acid is considered a promising energy carrier and hydrogen storage material for a carbon-neutral economy. We present an inexpensive system for the selective room-temperature photocatalytic conversion of formic acid into either hydrogen or carbon monoxide. Under visible-light irradiation (λ>420 nm, 1 sun), suspensions of ligand-capped cadmium sulfide nanocrystals in formic acid/sodium formate release up to 116±14 mmol H2 g(cat)(-1) h(-1) with >99% selectivity when combined with a cobalt co-catalyst; the quantum yield at λ=460 nm was 21.2±2.7%. In the absence of capping ligands, suspensions of the same photocatalyst in aqueous sodium formate generate up to 102±13 mmol CO g(cat)(-1) h(-1) with >95% selectivity and 19.7±2.7% quantum yield. H2 and CO production was sustained for more than one week with turnover numbers greater than 6×10(5) and 3×10(6), respectively.
authors.affiliation: Christian Doppler Laboratory for Sustainable SynGas Chemistry, Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge (UK) http://www-reisner.ch.cam.ac.uk.
authors.forename: Moritz F
authors.initials: MF
authors.lastname: Kuehnel
authors.affiliation: Christian Doppler Laboratory for Sustainable SynGas Chemistry, Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge (UK) http://www-reisner.ch.cam.ac.uk.
authors.forename: David W
authors.initials: DW
authors.lastname: Wakerley
authors.affiliation: Christian Doppler Laboratory for Sustainable SynGas Chemistry, Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge (UK) http://www-reisner.ch.cam.ac.uk.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Orchard
authors.affiliation: Christian Doppler Laboratory for Sustainable SynGas Chemistry, Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge (UK) http://www-reisner.ch.cam.ac.uk. reisner@ch.cam.ac.uk.
authors.forename: Erwin
authors.initials: E
authors.lastname: Reisner
keywords: CdS; formic acid; hydrogen; photocatalysis; quantum dots