We have been able to achieve a precise temperature resolved atomic-scale understanding of the reaction mechanism at the [RuH6] catalytic center, its unique thermodynamics, and kinetic aspects that enable exceptional low-temperature activity. These scientific insights need to be exploited towards optimizing complex transition metal hydrides as ammonia catalysts as well as exploring a newer class of materials that can replicate the behavior of [RuH6] catalytic center in the pursuit of renewables powered decentralized room temperature/pressure ammonia synthesis.