Corrosion and catalytic properties of electrodeposited nanocrystalline molybdenum

Molybdenum (Mo) is a less toxic alternative to chromium for protective coatings. Mo possesses similar properties to Cr, although its electrochemical properties, particularly its passive behavior, have been less studied. We compare the passive behavior of electrodeposited Mo coatings to that of bulk metallic Mo in 3.5% sodium chloride (NaCl) solution. The results demonstrate a strong correlation between the microstructure and passive properties of the coating. Electrodeposited Mo has a higher tendency to passivate, a higher passive current density, and a larger passivation window compared to bulk Mo in 3.5% NaCl. The enhanced electrochemical behavior of the Mo coating is attributed to its nanometric structure and increased electrochemically active surface area. This study highlights the potential for the use of electrodeposited Mo as a safer and more environmentally friendly alternative to Cr coatings.