AbstractSingle-atom confined materials (SACMs) have been widely researched as catalysts in many fields within recent years. However, this class of materials may not only serve as a catalyst but also as a support material for certain reactions. Here we propose a general strategy to use SACMs as supports for tuning loaded noble metal (e.g., Ru) nanoparticles with enhanced catalytic activity. As a proof of concept, a nickel single-atom confined nitrogen-doped carbon nanotube (NCNT) superstructure is prepared as a support to load noble metal Ru for catalytic wet air oxidation of acetic acid. Improved catalytic activity with a mineralization rate of ~97.5% is achieved. Further, adsorption configurations based on DFT calculations also confirm our deduction that the introduction of single-atom Ni changes the intrinsic property of NCNTs and affects the loaded active Ru nanoparticles.