(569at) Highly Active Ammonia Synthesis Catalysts Supported on Promoted Laser-Induced Graphene

Ammonia (NH₃) is a critical chemical because of its extensive use for the fertilizer that sustains the food for half of the world population. The current industrial NH₃ manufacturing follows the Haber-Bosch process, employing iron catalysts at high pressure and temperature. NH₃ manufacturing consumes 1–2% of global energy and emits over 1% of CO₂. Designing innovative catalysts has been a subject of research since the discovery of Haber-Bosch process. In 1980s, Ruthenium (Ru)-based catalysts have been found as an alternative to iron, enabling catalytic conversion of reactants to ammonia at lower pressure and temperature. High surface area graphite-supported Ru catalysts with alkali promoters were first demonstrated in industrial scale. While the utilization of Ru-based catalysts supported on carbonaceous materials signifies a notable advancement, its widespread application is hindered by the instability of the support material, primarily caused by methanation. To address this challenge, the support has been treated thermally at elevated temperatures or chemically in harsh conditions with the goal to improve the resistance to deactivation and ensure the uniform dispersion of Ru in bulk catalysts. Treating the carbon support imposes an additional challenge to design of Ru-based catalysts. Herein, we report a novel carbon-based support (Laser Induced Graphene) for Ru-catalyst that is easy to fabricate at scale and does not need any pretreatment. LIG-supported catalysts produce NH₃ at a comparatively higher rate. Our results suggest that the promoted LIG-supported Ru catalyst does not show any sign of deactivation. The catalytic activities upward of 22000 μmol g^-1 h^-1 at 400 ºC and 10 barg. A comprehensive investigation of the interaction between the support and active metal is performed utilizing various characterization techniques to elucidate the underlying mechanisms of LIG support improvement in synthesis rate. Detailed findings regarding the catalytic activity and mechanism under diverse conditions will be presented.