Microwave-assisted ammonia synthesis over Cs-Ru/CeO2 catalyst at ambient pressure: Effects of metal loading and support particle size

Industrially, ammonia is produced by Haber-Bosch process under high temperatures and pressures, consuming more than >2% of the world's energy production. This paper presents microwave-assisted catalytic synthesis of ammonia operated at atmospheric pressure and temperatures from 260 to 360 °C. A Cs-promoted Ru catalyst supported on cerium oxide with different metal loading (4–24 wt% Ru) and support particle size (25 nm, 50 nm and 5 μm) was investigated. The small size cerium oxide support resulted in the highest activity while the large cerium oxide support was less favorable, leading to lower activity associated to large Ru particle size and lower dispersion.