Size control of Pt nanoparticles with stabilizing agent for better utilization of the catalyst in fuel cell reaction

Abstract

In this investigation, tetrabutylammonium bromide (TBAB) has been used as the stabilizing agent during synthesis of 20% Pt on Vulcan XC-72 carbon support by the sodium borohydride reduction method. Crystallographic and morphological properties of the prepared electrocatalysts as well as their surface area were determined employing the respective techniques such as X-ray diffraction, transmission electron microscopy, and Brunauer–Emmet–Teller method. TBAB in the chemical deposition bath was found to control the size of nanoparticles by preventing the metal particles to aggregate during the reduction process without interfering with the deposition phenomenon. The catalysts were further characterized electrochemically by the help of cyclic voltammetry, steady state polarization, chronoamperometry, and impedance spectroscopy confirmed that the optimal use of tetrabutylammonium bromide produces fine grain Pt nanoparticles acting as the electrocatalyst for ethanol oxidation and can successfully prevent the use of excess of Pt that usually remain unutilized in the bulk of the catalyst.