Constructing Efficient Nickel Catalysts on CeO_x Nanoparticles Stabilized Using γ-Al₂O₃ to Catalyze Ammonia Decomposition for Hydrogen Production

Highly efficient oxide–metal interfaces in solid catalysts play a crucial role in numerous heterogeneous catalysis applications. In this work, an active and stable interface is fabricated between Ni and CeO 2 nanoparticles, which are stabilized using an Al 2 O 3 support, and it enormously boosts the catalytic performance for the NH 3 decomposition reaction. Systematic characterizations demonstrate that the small CeO 2 nanoparticles on the Al 2 O 3 support optimize the dispersion of Ni nanoparticles and modulate the reducibility of the interfacial Ni atoms, which directly correlate with the enhancement of the catalytic reactivity and stability. Moreover, in situ Raman and TPR results illustrate that the abundant surface-defective structure over small CeO 2 nanoparticles augments the adsorption and activation sites of NH 3 molecules for the Ni-CeO x /Al 2 O 3 catalyst. This work deepens the understanding of the synergistic effect between active metal and oxides and provides a facile strategy for designing efficient NH 3 decomposition catalysts.