Highlights
  1. An elementary reaction model for ammonia protonic ceramic fuel cells was proposed.
  2. Complex ammonia decomposition/electrochemical reaction steps were deconvoluted.
  3. The ammonia-hydrogen performance ratio reaches 95% by accelerating ammonia decomposition at anode.
  4. Anode parameters affect cell performance by affecting the ammonia decomposition and charge transfer reaction.
  5. Strategies for the subsequent design of ammonia protonic ceramic fuel cells were proposed.