Recent progress and perspectives of catalytic ammonia synthesis

As a cornerstone of the global chemical industry and agriculture, ammonia (NH₃) synthesis faces a pressing challenge for a sustainable future due to the harsh conditions used and substantial CO₂ emission in the conventional Haber-Bosch process. This has spurred extensive research into alternative pathways to moderate the operation conditions and to reduce carbon footprint. Diverse thermal catalysts, novel reaction routes and in-depth fundamental understanding have thus been explored over the past decades. This review highlights the progress of advanced catalysts and emerging mechanisms discovered in ammonia synthesis and identifies key challenges to industrial deployment, such as high costs, unsatisfactory stability, weak impurity tolerance, economic viability, etc., which are pushing the boundaries of thermal catalytic nitrogen fixation. It further provides a forward-looking perspective on the key challenges and emerging opportunities in future research directions, including AI-assisted discovery of catalysts, mechanistic analysis and ultimately achieving green ammonia production from green hydrogen.