Sequential catalytic growth of sulfur-doped carbon nanotubes and their use as catalyst support

A sequential process has been developed to produce sulfur-doped carbon nanotubes (7% w/w sulfur) on iron supported catalysts. In this procedure it is necessary to first activate the iron catalyst to initiate the growth of all-carbon CNTs from ethylene, prior to growth sulfur doped CNTs from thiophene. The resulting sulfur-doped carbon nanotubes constitute an excellent support for the anchoring of very small (1.8 nm) palladium nanoparticles. This Pd based catalyst is very active for ethanol aerobic oxidation to acetic acid.