Highly dispersed Pt nanoparticles immobilized on 1,4-benzenediamine-modified multi-walled carbon nanotube for methanol oxidation.

We demonstrate the use of molecular monolayers to enhance the nucleation of electrocatalytically active platinum (Pt) nanoparticles onto multi-walled carbon nanotubes (MWCNTs). The MWCNT is embedded within the 1,4-benzenediamine shell (NH(2)-MWCNT) with large amounts of amino groups outside on the nanotube surfaces. Subsequent deposition of platinum nanoparticles led to high densities of 2 to 5 nm diameter platinum nanocrystals uniformly deposited along the length of the MWCNTs (Pt/NH(2)-MWCNTs). The structure and nature of the resulting Pt/NH(2)-MWCNTs composites were characterized by transmission electron microscopy and X-ray diffraction. Electrochemical measurements show that the molecular monolayers do not impede redox behavior of the electrode, and measurements of the electrocatalytic oxidation of methanol show very high catalytic efficiency compared with commercial E-TEK Pt/C (20 wt%) catalysts, which is crucial for anode electrocatalysis in direct methanol fuel cells.