On the operating mode of bimetallic systems for environmental remediation.

This letter challenges the concept that Fe(0)/Me(0) bimetallic systems enhance contaminant reduction on Me(0) surfaces. It is shown on a pure thermodynamic perspective that any enhancement of contaminant reduction by Fe(0) in the presence of a second more electropositive elemental metal (Me(0)) is the result of an indirect process resulting from iron corrosion. This demonstration validates the concept that aqueous contaminant removal in the presence of Fe(0) mostly occurs within an in situ generated oxide film on Fe(0).