Electronic metal-support interaction enhanced ammonia decomposition efficiency of perovskite oxide supported ruthenium

Ammonia has been considered as a promising hydrogen carrier with high energy storage density and easy transport. Here, we report the ruthenium (Ru) nanoparticles supported on LaAlO3, a typical ABO3 perovskite oxide, as an efficient catalyst for ammonia decomposition. By tailoring the cation substitution of La3+ by Sr2+, the electronic properties of support materials were modulated, which exerts an impact on the electronic state of Ru active sites. It is found that the Ru/La0.8Sr0.2AlO3 catalyst has a high hydrogen formation rate and low activation energy. In situ spectroscopic investigation and NH3 temperature programmed desorption (NH3-TPD) analyses indicate the electron-rich state of metallic Ru on the La0.8Sr0.2AlO3 support, which promotes associative desorption of N atoms and accelerates NH3 decomposition reactions. This study provides a universal strategy of aliovalent cation substitution to engineer the electronic properties of metal/oxide catalysts as well as their catalytic activities.