Low-Cost Pb-Co-Sn film for the Oxygen Evolution Reaction in Acid Media

Abstract

The oxygen evolution reaction (OER) plays an important role in several industrial processes. However, the high overpotential that the OER requires to take place, has resulted in high costs associated with precious metals used in anodes that catalyze this reaction. Substitute elements, among them Co, have been investigated in order to decrease their price, herein, highlight Pb-Co electrodes that achieved an important decrease in the overpotential needed for the OER. Even though the electrocatalyst ability showed by the Pb-Co anode was considerably high, the current densities achieved were too low to compete with commercial anodes. Therefore, the efficiency to produce O2 should be increased. The aim of this work was to develop a Pb-Co-Sn film, through anodic electrodeposition, that enables an efficient production of O2 coupled with stability, low-cost and low overpotential. In order to know the morphological, microstructural and chemical composition, a full characterization of the developed film was carried out. The obtained Pb-Co-Sn film showed higher electrochemical performance than conventional Pb-Ca-Sn anodes, with an overpotential of ∼0.27 V vs NHE at 500 Am−2, 68% lower than a conventional Pb-Ca-Sn anode.

Revealing the Reaction Mechanism of Lead Anodes in the Manganese Electrowinning Process

“…During the back-scan process, an oxidation peak A3 also emerges. The cause of the A3 peak is still controversial . Some researchers suggest that this peak is due to the shrinkage of the anode film, as the volume becomes smaller during the conversion of lead sulfate to lead dioxide .…”

“…The cause of the A3 peak is still controversial. 26 Some researchers suggest that this peak is due to the shrinkage of the anode film, as the volume becomes smaller during the conversion of lead sulfate to lead dioxide. 22 This will make the lead anode re-expose the fresh anode surface and the sulfate ions enter into the matrix, producing lead sulfate as well as basic lead sulfate.…”