Facile synthesis of precious-metal single-site catalysts using organic solvents

• Published in: Nature chemistry 2020-06, Vol.12 (6), p.560-567
• Main Authors: Sun, Xi, Dawson, Simon R., Parmentier, Tanja E., Malta, Grazia, Davies, Thomas E., He, Qian, Lu, Li, Morgan, David J., Carthey, Nicholas, Johnston, Peter, Kondrat, Simon A., Freakley, Simon J., Kiely, Christopher J., Hutchings, Graham J.
• Format: Article
• Language: English
• Subjects: 639/638/224; 639/638/77; Acetone; Acetylene; Acidic oxides; Activated carbon; Analytical Chemistry; Aqueous solutions; Biochemistry; Boiling points; Catalysts; Chemical synthesis; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Gold; Hydrochlorination; Impregnation; Inorganic Chemistry; Metals; Organic Chemistry; Organic solvents; Oxidation; Palladium; Physical Chemistry; Platinum; Polarity; Selectivity; Solvents; Vinyl chloride
• ISSN: 1755-4330; 1755-4349
• DOI: 10.1038/s41557-020-0446-z

Single-site catalysts can demonstrate high activity and selectivity in many catalytic reactions. The synthesis of these materials by impregnation from strongly oxidizing aqueous solutions or pH-controlled deposition often leads to low metal loadings or a range of metal species. Here, we demonstrate that simple impregnation of the metal precursors onto activated carbon from a low-boiling-point, low-polarity solvent, such as acetone, results in catalysts with an atomic dispersion of cationic metal species. We show the generality of this method by producing single-site Au, Pd, Ru and Pt catalysts supported on carbon in a facile manner. Single-site Au/C catalysts have previously been validated commercially to produce vinyl chloride, and here we show that this facile synthesis method can produce effective catalysts for acetylene hydrochlorination in the absence of the highly oxidizing acidic solvents previously used. Au/C single-site catalysts have been validated commercially for acetylene hydrochlorination, but they have previously been prepared using highly oxidizing acidic solvents or additional ligands. It has now been shown that they can be made by impregnation of a metal salt from an acetone solution—generating catalysts with comparable activity to those synthesized by the other methods.