Method for supporting platinum on single-walled carbon nanotubes for a selective hydrogenation catalyst

We have prepared a novel material, consisting of Pt particles supported on purified single-walled carbon nanotubes (SWNTs), representing the first rep orted metal-loaded SWNT material. The material contains 10 wt % Pt on entan gled SWNT bundles consisting of 20-100 nanotubes each. The average Pt parti cle size is 1-2 nm, High-resolution transmission electron microscopy (HRTEM ) observations combined with electron energy-loss spectroscopy (EELS) indic ate chemical bonding between Pt and the SWNT surfaces. This bonding is acco mplished presumably by ion exchange on carboxylic acid sites created on the nanotube surfaces by slow wet oxidation in dilute HNO8. In addition, a sim ple SWNT purification scheme requiring no filtration was developed for the preparation of this material. The purification results in a well-defined st ructure for the metal support useful for investigating the role of this mat erial as a heterogeneous catalyst and the effects of metal-support interact ions (MSI). Preliminary kinetics measurements of the activity of this mater ial for the selective partial hydrogenation of 3-methyl-2-butenal (prenal) to 3-methyl-2-butenol (prenol)-a representative reaction important in the f ine chemicals industry-indicates the desired catalytic selectivity above 75 degreesC, demonstrating a utility of this material that can be optimized i n future work.