Catalytic Perchlorate Reduction Using Iron: Mechanistic Insights and Improved Catalyst Turnover

Perchlorate is a non-coordinating and kinetically inert anion commonly used in solid rocket fuels and explosives. Upon introduction to the environment, it is a pervasive groundwater pollutant that poses remediation challenges. There remain few homogeneous systems capable of deoxygenating perchlorate to chloride, and the reported catalysts suffer from deactivation as the concentration of chloride increases during catalysis. This report improves the turnover number of perchlorate reduction by an iron catalyst containing a secondary coordination sphere by an order of magnitude. The use of a zinc reagent mitigates chloride inhibition and promotes catalyst turnover. Additionally, the initial rate of perchlorate reduction was examined using time-resolved UV-visible spectroscopy, furnishing insights into the mechanism of perchlorate reduction.