Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Au-Pd/TiO2 Catalysts
Dan I. Enache,1
Jennifer K. Edwards,1
Philip Landon,1
Benjamin Solsona-Espriu,1
Albert F. Carley,1
Andrew A. Herzing,2
Masashi Watanabe,2
Christopher J. Kiely,2
David W. Knight,1
Graham J. Hutchings1*
The oxidation of alcohols to aldehydes with O2 in place of stoichiometric oxygen donors is a crucial process for the synthesis of fine chemicals. However, the catalysts that have been identified so far are relatively inactive with primary alkyl alcohols. We showed that Au/Pd-TiO2 catalysts give very high turnover frequencies (up to 270,000 turnovers per hour) for the oxidation of alcohols, including primary alkyl alcohols. The addition of Au to Pd nanocrystals improved the overall selectivity and, using scanning transmission electron microscopy combined with x-ray photoelectron spectroscopy, we showed that the Au-Pd nanocrystals were made up of a Au-rich core with a Pd-rich shell, indicating that the Au electronically influences the catalytic properties of Pd.
1 School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, UK CF10 3AT.
2 Center for Advanced Materials and Nanotechnology, Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015–3195, USA.
* To whom correspondence should be addressed. E-mail: hutch{at}cf.ac.uk
