Mechanistic Insights into pH-Controlled Nitrite Reduction to Ammonia and Hydrazine over Rhodium

An unintended consequence of industrial nitrogen fixation through the Haber–Bosch process is nitrate (NO3–) and nitrite (NO2–) contamination of ocean, ground, and surface waters from fertilizer runoff. Transition-metal catalysts, particularly those based on Pd, are effective in removing NO3–/NO2– through reduction to N2 or NH4+. Pd is regarded as the most effective metal for NO3–/NO2– reduction, and as such, few studies have thoroughly explored...