Hydrogen is rapidly emerging as a pivotal clean energy carrier for both stationary and transport applications. However, the storage of hydrogen as compressed gas at high pressures poses significant challenges in terms of cost, transportation, and safety. Chemical storage, particularly using compounds like ammonia, has emerged as a viable alternative due to its high hydrogen content and narrow flammable range. This study investigates the catalytic decomposition of ammonia under an electric field using Ni based La2O3 catalysts. The catalytic performance is evaluated in terms of ammonia conversion and energy efficiency. High catalytic activity is obtained in the presence of 15 wt%NiO/La2O3, the energy efficiency is 0.29 mmol/kJ. This is attributed to the semiconducting properties of NiO. Catalyst characterization techniques, including X-ray diffraction, transmission electron microscopy, and photoelectron spectroscopy, provide insights into catalyst morphology, chemical composition before and after reaction. It is shown that hydroxylation of La2O3 proceeds during ammonia decomposition and a reaction mechanism is provided.