A new catalyst strategy developed at Institute of Science Tokyo uses BaSi2 as a support for nickel and cobalt to decompose ammonia at lower temperatures. By forming unique ternary transition metal–nitrogen–barium intermediates that facilitate nitrogen coupling, the system lowers the energy barrier for ammonia decomposition. This enables nickel- and cobalt-based catalysts to achieve high hydrogen-production activity at reduced temperatures, matching the performance of ruthenium while relying on Earth-abundant metals for cleaner hydrogen generation.