Fabrication and electrochemical activity of carbon nanotubes decorated with PtRu nanoparticles in acid solution

A series of carbon nanotubes (CNTs) decorated with bimetallic platinum/ruthenium nanocatalysts were fabricated to investigate their electrochemical activities in acid solution. These PtRu/CNT composites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD). and N-2 physisorption. The crystalline size of PtRu nanocatalysts generally decreased with Ru atomic ratio, i.e., from 4.34 to 2.77 nm. The specific surface areas and pore size distributions of PtRu/CNT composites were slightly altered after the PtRu deposition. Cyclic voltammetry measurements in 1M H2SO4 showed that Pt75Ru25/CNT electrode has the greatest activity in electrochemical adsorption and desorption of hydrogen, i.e., the ratio of electrochemical surface coverage: 84.6%. This enhancement of electrochemical activity was attributed to two possible reasons: (i) addition of Ru in the bimetallic catalysts leads to reduce the required potential for water electrolysis and thus the associated carbon oxidation; (ii) the presence of Ru in the bimetallic alloys acts an important role in regenerating inactive Pt-COads sties. (c) 2007 Elsevier B.V. All rights reserved.