The 𝐶 𝑁𝐻 3 𝑜𝑢𝑡 reaches its peak at 350-450 °C, and the peak temperature increases at higher pressure. The equilibrium concentration of ammonia is reduced at higher temperature and increase at larger pressure. Then, the reaction rates in Fig. is influenced by the chemical equilibrium in the high-temperature region. The order of catalytic activity is Ru/Ba-Ca(NH2)2 > Ru/Pr2O3 > Ru/C in all pressure and temperature ranges (see Supplementary information).