Promotion of Low-Temperature Catalytic Activity of Ru-Based Catalysts for Ammonia Decomposition via Lanthanum and Cesium Codoping

Abstract

were synthesized via the wet impregnation method, which were then used for hydrogen production from ammonia decomposition. Of the catalysts prepared, RuLaCs/Al 2 O 3 exhibited the highest lowtemperature catalytic activity and greatest stability, achieving a NH 3 conversion of >99% at the temperature as low as 450 °C. It was discovered that the addition of La and Cs was able to promote the recombinative desorption of surface nitrogen atoms at active sites through the role of electron donor, thus promoting ammonia decomposition. The synergistic effect of La and Cs was thought to be the reason for significantly enhancing the catalytic performance of the catalyst. The continuous tests of more than 100 h indicated no activity deterioration for the developed catalysts, demonstrating an excellent stability and great potential for future commercial applications.

Ni-Ru supported on CeO2 obtained by mechanochemical milling for catalytic hydrogen production from ammonia

“…Currently, research on the catalysts for ammonia decomposition, aimed at hydrogen production, still focuses on ruthenium, with nickel and cobalt emerging as primary alternatives due to their cost-effectiveness. Alternative preparation techniques, including coprecipitation 5 or sol-gel 6 , 7 methods, are being investigated, together with the effect of different promoters, 8 , 9 , 10 supports, 11 , 12 or active phase precursors 13 on the catalyst activity. Moreover, the utilization of oxide combinations, such as Al-La-Ce 14 or CeO 2 -promoted MgAl 2 O 4 , 15 as catalyst supports, has allowed the enhancement of the stability of ruthenium, and this effect has been ascribed to the high presence of oxygen vacancies in the support structure.…”