A new generation pathway of singlet oxygen in heterogeneous single–atom Mn catalyst/peroxymonosulfate system

•Mn SAC/PMS was designed to trigger radical and nonradical hybrid system.•The removal of target pollutant was dependent on the nonradical–oxidation.•A novel generation pathway of singlet oxygen under acidic and neutral conditions was explored.•A new mechanism for the synergistic effect of radical and nonradical pathways was proposed.