Theoretically Evaluating Transition Metal Activated Two-Dimensional Bilayer Tetragonal AlN Nanosheet for High-Performance HER/OER/ORR Electrocatalysts

•A novel two-dimensional AlN substrate anchoring transition metal atoms is proposed as HER/OER/ORR electrocatalyst instead of precious metals.•The adsorption behaviors of more than a dozen TM-doped systems on several potential sites are investigated to screen for efficient catalysts among many candidate materials.•The relevant descriptors, COHP, and bader charge, etc. are carried out to describe the high activity intrinsic mechanism.