The behavior of HBF4 at Pt single crystal electrodes

Based on voltammetric experiments, we discuss the behavior of tretrafluoroborate anion (BF4-) at Pt single crystal electrodes: Pt(1 1 1), Pt(1 1 0) and Pt(1 0 0). The BF4- is reported as a non-coordinating anion, but very few works in electrochemistry have been explored systematically its features at ordered surfaces. In this work we report initially the experiments made with the tetrafluoroborate acid (HBF4) as received, which presented a redox peaks associated to arsenic contamination. The arsenic contamination was removed by the electrolysis of the solution, which allowed studying the BF4- behavior at the three platinum basal planes without interference. The BF4- anion chemisorb on the Pt(1 1 1) surface with enough strength to suppress part of the characteristics of the voltammogram recorded in perchloric acid. For Pt(1 1 0) the increase of BF4- anion concentration leads to a small modification of the Pt(1 1 0) profile voltammogram. However, for Pt(1 0 0) the cyclic voltammograms features almost match with the characteristics fingerprint of a well ordered Pt(1 0 0) surface in perchloric acid. (C) 2010 Elsevier B.V. All rights reserved.