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

Abstract

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 CeO2 nanoparticles, which are stabilized using an Al2O3 support, and it enormously boosts the catalytic performance for the NH3 decomposition reaction. Systematic characterizations demonstrate that the small CeO2 nanoparticles on the Al2O3 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 CeO2 nanoparticles augments the adsorption and activation sites of NH3 molecules for the Ni-CeOx/Al2O3 catalyst. This work deepens the understanding of the synergistic effect between active metal and oxides and provides a facile strategy for designing efficient NH3 decomposition catalysts.