Eco-friendly mechano-chemical synthesis of innovative metal supported catalysts for energy and environmental applications

Ammonia has emerged as a promising candidate for hydrogen's chemical storage: with its high hydrogen content and ease of liquefaction at low pressure, ammonia is easier to transport and store, requiring minimal energy. Ammonia also benefits from established global production capabilities and an existing worldwide transportation network. Hydrogen can then be extracted through the catalytic decomposition of ammonia, which produces gaseous hydrogen without any side reactions. This process is a COx-free method of hydrogen production, as no CO2 or CO are directly emitted, offering a significant advantage over other hydrogen storage solutions. The development of efficient and cost-effective catalysts for hydrogen production from ammonia is currently one of the key challenges for the practical use of ammonia as an energy carrier. Due to its significant impact on current hydrogen research, the importance of this hydrogen production method, and the substantial economic and academic opportunities it presents, ammonia decomposition was selected as the central focus of this Ph.D. project. The research project aims at developing eco-friendly methods for catalyst production, reducing the environmental impact of their preparation at both laboratory and industrial scale. To achieve these goals, a specific material design strategy will be employed, involving the use of mechano-chemical synthesis as a green method for catalyst preparation, along with the development of novel support materials with a reduced environmental impact. Mechanochemistry offers great potential for catalyst preparation, providing numerous opportunities to create sustainable catalysts. It has a significantly lower environmental impact compared to traditional wet preparation methods and can be easily scaled for industrial production. For these reasons, dry mechanochemical milling has been chosen as the method for preparing ammonia decomposition catalysts in this thesis. Furthermore, the collaboration with an industrial partner in developing new strategies to reduce the environmental impact of large-scale catalyst production was essential in understanding how to design a synthesis procedure that yields high-performance catalysts with a low carbon footprint.