Production of biocarbon catalysts for NOx decomposition, WGS and RWGS

Overview & Synopsis

This work proposes an innovative approach to the production, characterization and use of biocarbon catalysts for energy and environment-related applications, in order to reduce the cost and impact of the commercial catalysts currently in use. The work developed here promotes a circular economy approach in the way that plants from phytoremediation have been used for the production of eco-friendly biocarbon catalysts. They were used for the production of energy vectors such as hydrogen by direct and reverse water-gas shift reaction (WGS and RWGS respectively), as well as for the decomposition of NOx pollutants (deNOx). Biocarbon catalysts were produced from willow and fern with a controlled metal content introduced by wet impregnation before or after pyrolysis at 800°C to imitate hyperaccumulation (>3 g metal/kg biocarbon) in a porous carbon support. The resulting catalysts were tested in deNOx, as well as WGS and RWGS reactions, and the associated experimental equipments were developed and optimized during this thesis work. They were characterized in terms of composition, structure and thermal stability, before and after use. For the three reactions, the catalysts showed high selectivity and conversion, facilitated by the catalytic metals whose activity was enhanced by the inherent metals. The presence of surface oxygen functions and a high specific surface area (