Hydrogen is considered an efficient alternative fuel. Most of the hydrogen produced on a large scale mainly comes from the steam reforming of natural gas, which is considered the most established and least expensive method. Although water electrolysis is also a well-established technique used to produce hydrogen, it causes high energy losses. The generation, storage, and transportation of hydrogen as an alternative fuel have been extensively studied during the last few decades. Given the challenges in generating and storing hydrogen for portable applications, ammonia has been proposed as an alternative for on-site hydrogen production through its decomposition. In this study, the catalytic decomposition of ammonia was conducted to produce CO₂-free hydrogen. Ru-based catalysts have been recognized as efficient catalysts for ammonia decomposition under mild reaction conditions. For Ru-based catalysts, the supports were found to play a profound role in the ammonia decomposition process. CeO₂ is an efficient support for ammonia decomposition, but as it is expensive, CeO₂ cannot be used for large-scale industrial applications. Therefore, Ru-based catalysts were prepared using CeO₂-impregnated Al₂O₃ supports. CeO₂-impregnated Al₂O₃ supports were prepared in various Ce/Al molar ratios. The catalysts prepared from CeO₂-impregnated Al₂O₃ supports with molar ratios of 0.5 and 1.0 showed a comparative efficiency to those prepared from a pure CeO₂ support. The presence of less expensive Al₂O₃ in bulk while achieving comparable efficiency to that of a pure CeO₂-supported Ru catalyst resulted in cost-effective and efficient catalysts for ammonia decomposition.