What is the effect of trace impurities in perchloric acid on the blank voltammetry of Pt(111)?
Label:chem
Topic
Perchloric acid (HClO₄) is commonly used in electrochemical studies to characterize single-crystal surfaces such as Pt(111), as it is generally assumed that no specific adsorption of perchlorate anions occurs. However, trace impurities, particularly nitrates and sulfates, present in high-purity HClO₄ solutions can significantly affect the voltammetric response of Pt(111).
From: "Effect of trace impurities in perchloric acid on blank voltammetry of Pt(111)", Electrochimica Acta, Volume 466, 20 October 2023, 143035
Answer
Trace impurities of nitrate and sulfate species in perchloric acid cause the charge quench of existing voltammetric peaks and the appearance of new peaks in the blank voltammetry of Pt(111). These impurities lead to site-blocking effects, reducing the charge density across the cyclic voltammogram (CV) of Pt(111) and affecting the efficiency of electrocatalytic processes such as the oxygen reduction reaction (ORR). The study suggests that these impurities should be minimized by using lower concentrations of HClO₄, cycling regularly into the hydrogen underpotential deposition (Hupd) region, and employing purification methods to remove trace-level impurities.
Return to Home
Chemical List
Knowledge you may be interested in