Radical inhibition mechanisms of ammonium sulfate on industrial organic pollutants in copper-catalyzed reactions

The inhibition of organic pollutants in thermal industrial systems, where metal catalysts and organic pollutant precursors coexist, requires mechanistic insights for targeted control. This study elucidates detailed inhibition mechanisms of ammonium sulfate suppresses toxic byproducts in widespread copper-catalyzed reactions from the micro perspectives of organic free radicals through dual pathways: (1) Organic radical regulation: In-situ EPR identified ortho -amino-tetrachlorophenoxy radicals as key intermediates, which resist dimerization into toxic products. The identified radical structure provides direct evidence supporting the proposed molecular mechanisms. (2) Catalyst deactivation: X-ray analysis demonstrated ammonium sulfate's occupation of Cu active sites and reduction of catalytic oxidation states. These findings provide a molecular-level framework for inhibiting pollutants in metal-rich industrial processes.