Single crystal MnOOH nanotubes for selective oxidative coupling of anilines to aromatic azo compounds

Catalytic synthesis of aromatic azo compounds by oxidative coupling of anilines using molecular oxygen represents a facile, green and valuable process; however, such an economical process suffers from poor catalytic activity and selectivity. Herein, novel single crystal MnOOH nanotubes with abundant Mn3+ sites and high oxygen defects were successfully synthesized. The catalyst exhibited high selectivity for oxidative coupling of anilines, achieving complete transformation into aromatic azo compounds under mild conditions, even at room temperature.