Ultra‐Fast Synthesis of Composite Oxide‐Supported Transition Metal Alloy as an Advanced Catalyst for Ammonia Decomposition

Abstract Ammonia decomposition reaction (ADR) has been extensively used to generate clear hydrogen in industry. Despite ruthenium (Ru) being the most active catalyst component for ADR, its exceptionally high price imposes severe limitations on its large‐scale application. Therefore, the development of cost‐effective and robust noble‐metal‐free ADR catalysts is highly desired, but it remains a challenge. Herein, a spray pyrolysis‐assisted method is reported for the ultra‐fast synthesis of strongly coupled composite oxide supports and transition metal alloy centers. The optimized catalyst, La 0.75 Sr 0.25 (FeCoNi) 1.7 O 3‐δ, exhibits outstanding ADR performance, achieving ≈98% ammonia conversion at 600 °C with remarkable stability over a period of 150 h. Further investigations reveal that the composite oxide support is enriched with numerous medium to strong basic sites. These sites play a crucial role in transferring electrons to the supported transition metal alloy, thus contributing to the rapid recombination and desorption of nitrogen atoms.