Catalytic Reduction of Aqueous Perchlorate at Neutral pH

High Resolution Image Download MS PowerPoint Slide Perchlorate (ClO 4 – ) is a pervasive and inert pollutant threatening human health. Catalytic reduction of ClO 4 – is imperative for water environment remediation and promising for space exploration. Previous catalysts using oxo Mo IV and Re V species required acidic pH to reduce aqueous ClO 4 – . Herein, we developed a ligand-enhanced Ru 0 nanoparticle catalyst for rapid ClO 4 – reduction by 1 atm H 2 at pH 7 and 20 °C. Molecular organic nitrogen ligands, particularly cis -1,2-diaminocyclohexane ( cis -DACH), accelerated Ru 0 -catalyzed ClO 4 – reduction by up to 80-fold. Nitrogen-functionalized carbon (NC) support also provided up to 5-fold acceleration. The final [ cis -DACH]Ru/NC catalyst demonstrated unprecedented activity and robustness for ClO 4 – reduction at neutral pH. Kinetic analyses and instrumental characterizations found that the nitrogen ligands not only boosted the reactivity of exposed Ru 0 sites by 63-fold (31-fold by cis -DACH and 2-fold by the NC support) but also enhanced ClO 4 – adsorption by 180%. This novel paradigm of tuning nanostructured catalysts by organic ligands will benefit environmental and energy applications for the degradation and utilization of ClO 4 – .