Experimental and microkinetic investigation of thermo-catalytic ammonia decomposition over a Ba-promoted Ru/Ni-BCZY catalyst for use in ammonia-fed protonic ceramic cells

Direct ammonia-fed Protonic Ceramic Cells (NH 3 -PCC) hold great promise for efficient energy generation, since ammonia can be used directly as fuel at the anode without the need of prior cracking to hydrogen. This study evaluates the catalytic activity of barium-promoted ruthenium catalysts supported on Ni-BCZY cermet particles in a packed-bed reactor, and provides a microkinetic model for simulation of the thermo-catalytic ammonia decomposition reaction. Among the catalysts tested, the 0.5 wt.% Ru and 1 wt.% Ba supported on a Ni-BCZY cermet exhibited the best performance, requiring less active material. The addition of Ru and Ba improved the catalytic activity of the bare Ni-BCZY cermet, which also shows catalytic activity due to Ni active sites. A new set of microkinetic model parameters is presented, combining Ba-promoted ruthenium and nickel surface steps. This model was used to conduct a parametric simulation, providing insights into the impact of the operating conditions. • Experimental and numerical investigation of ammonia decomposition over Ni-BCZY in a packed-bed reactor highlight the role of Ni as an active catalyst in a cermet. • The catalyst containing 0.5 wt.% Ru and 1 wt.% Ba on Ni-BCZY demonstrated the best performance among six different samples, making it the most suitable for NH₃-PCC applications. • A new microkinetic model is proposed to simulate the catalytic reaction, incorporating both Ru and Ni active sites