Synergistic Enhancement of Zinc Electrowinning Performance by Ti₂N Interlayer and CeMnO_x Powder Modification

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Industrial lead-silver (Pb-Ag) anodes in zinc electrowinning suffer from high oxygen evolution overpotential and rapid corrosion.
• These limitations reduce energy efficiency and anode lifespan, impacting the overall process economics.

Purpose of the Study:

• To develop advanced composite anodes that overcome the limitations of traditional Pb-Ag anodes for zinc electrowinning.
• To enhance electrocatalytic activity and improve the corrosion resistance and operational stability of anodes.

Main Methods:

• Fabrication of Ti-Ti2N-PbO2-CeMnOx (CMO) composite anodes.
• Electrochemical characterization including overpotential and Tafel slope measurements.
• X-ray Photoelectron Spectroscopy (XPS) analysis to determine surface composition and oxidation states.
• Accelerated polarization testing to evaluate corrosion resistance and service life.

Main Results:

• The CMO composite anode demonstrated a reduced overpotential (725 mV at 50 mA cm-2) and lower Tafel slope (102.92 mV dec-1), indicating faster oxygen evolution kinetics.
• XPS analysis confirmed an increased Mn3+ content, contributing to enhanced oxygen evolution reaction (OER) catalytic activity.
• The anode exhibited superior corrosion resistance, maintaining stability for 53 hours under accelerated polarization (2 A cm-2).

Conclusions:

• The Ti-Ti2N-PbO2-CeMnOx composite anode offers a promising alternative to conventional anodes in zinc electrowinning.
• The synergistic effects of the Ti2N interlayer and CMO coating provide excellent electrocatalytic activity and durability.
• This development paves the way for more efficient and stable zinc electrowinning processes using dimensionally stable anodes (DSAs).