Stable metal nitrides (MN) are promising materials to fit the future “green” ammonia–hydrogen nexus. Either through catalysis or chemical looping, the reductive hydrogenation of MN to MN1–xis a necessary step to generate ammonia. However, encumbered by the formation of kinetically stable M-NH1─3surface species, this reduction step remains challenging under mild conditions. Herein, we discovered that deleterious Ti-NH1─3accumulation on TiN can be circumvented photochemically with supported single atoms and clusters of platinum (Pt1-Ptn) under N2–H2conditions. The photochemistry of TiN selectively promoted Ti-NH formation, while Pt1-Ptneffectively transformed any formed Ti-NH into free ammonia. The generated ammonia was found to originate mainly from TiN reduction with a minor contribution from N2activation. The knowledge accrued from this fundamental study could serve as a springboard for the development of MN materials for more efficient ammonia production to potentially disrupt the century-old fossil-powered Haber–Bosch process.