Catalyst Design Strategies for Ammonia Synthesis from Nitric Oxide

Abstract Ammonia synthesis from nitrogen oxides (NO x ) offers a promising alternative to conventional N 2 –H 2 processes by bypassing the energy challenge of N≡N bond cleavage while simultaneously processing major air pollutants. This review outlines our recent progress in the NO x -To-Ammonia (NTA) reaction using CO or H 2 as a reductant. Catalysts based on Pt/TiO 2 , Cu/CeO 2 , and Ni/CeO 2 revealed distinct mechanistic pathways involving formate and isocyanate (NCO) intermediates rather than direct NO reduction. Optimization of the TiO 2 crystalline phase and preparation improved Pt dispersion and boosted activity. Cu/CeO 2 achieved good low-temperature performance without requiring precious metals. Ni/CeO 2 and bimetallic Ni–Pt/TiO 2 catalyzed an NCO-mediated route. Moreover, partially reduced Pt/TiO 2–δ nearly eliminated N 2 O byproducts. These advances demonstrate that rational catalyst design targeting key intermediates enables selective low-temperature ammonia synthesis from NO x , so promoting a sustainable strategy for energy-efficient nitrogen utilization. Fullsize Image