Ammonia decomposition over low-loading ruthenium catalyst achieved through “adiabatic” plasma reactor

Electrified catalytic processes for ammonia (NH 3 ) decomposition have been considered as essential technologies for distributed CO x -free hydrogen production. Here we show that efficient NH 3 decomposition can be achieved over low-loading Ru/Al 2 O 3 using an adiabatic dielectric barrier discharge (DBD) plasma reactor. Specifically, we demonstrate that the activity of NH 3 decomposition in the adiabatic plasma reactor is up to 4.9 times higher than that under nonadiabatic conditions. The NH 3 conversion was 73% (in the adiabatic plasma reactor) over the 0.05 wt% Ru/Al 2 O 3 catalysts at a plasma power of 19 W, whereas, the conversion is only 15% when performed in the nonadiabatic plasma reactor, moreover, the catalyst was almost inactive in the thermal catalytic NH 3 decomposition. Additionally, nearly 100% NH 3 conversion was achieved over the 0.5 wt% Ru/Al 2 O 3 catalyst at 19 W or over higher Ru loading catalysts at lower powers. We suggested that more efficient NH 3 decomposition was attributed to the enhanced synergy between plasma-activated radicals ·NH x and vibrationally excited NHv3, and the catalytically active Ru sites when using the adiabatic plasma reactor – in contrast to the nonadiabatic counterpart.