New catalysts based on reduced graphene oxide for hydrogen production from ammonia decomposition

Promising and highly novel catalysts based on ruthenium (Ru) supported on reduced graphene oxide were synthesized, characterized and tested for COx-free hydrogen generation by catalytic ammonia decomposition. Metal loading and amount of a pre-reducing agent clearly affect the catalytic properties of...

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Detalhes bibliográficos
Autores: Pinzón García, Marina, Aviles-Garcia, Osmin, Osa Puebla, Ana Raquel de la, Consuegra, Antonio de Lucas, Sánchez Paredes, Paula, Romero Izquierdo, Amaya
Formato: artículo
Fecha de publicación:2022
País:España
Recursos:Universidad de Castilla-La Mancha
Repositorio:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/29868
Acesso em linha:https://hdl.handle.net/10578/29868
Access Level:acceso abierto
Palavra-chave:Ammonia decomposition
Ruthenium
Reduced graphene oxide
Hydrogen production
Descomposición de amoníaco
Rutenio
Óxido de grafeno reducido
Producción de hidrógeno
Descrição
Resumo:Promising and highly novel catalysts based on ruthenium (Ru) supported on reduced graphene oxide were synthesized, characterized and tested for COx-free hydrogen generation by catalytic ammonia decomposition. Metal loading and amount of a pre-reducing agent clearly affect the catalytic properties of the final catalysts. A Ru loading higher than 2.5 wt% resulted in Ru particles of size higher than 5 nm, which were agglomerated, thus decreasing the amount of the most active sites (B5 type-sites) and therefore the ammonia conversion. Additionally, a graphene oxide (GO) hydrothermal pre-reduction with 2-chloroethylamine hydrochloride, led materials with a more ordered structure which is associated with a good electronic conductivity and, higher basicity. Optimal catalytic activity is achieved using a reducing agent/GO ratio of 5/3 (wt/wt) and a Ru loading of 2.5 wt%. Thus, 2.5Ru/10C-rGO catalyst resulted in excellent hydrogen (H2) production from ammonia decomposition, with an ammonia conversion close to 96% and hydrogen production rate of 9.1 mmolH2 gcat−1 min−1 at 400 °C. Reduced graphene oxide proved to be a suitable support in the development of nanosized Ru catalysts being the optimal one highly active in COx-free hydrogen generation during more than 60 h of reaction, providing virtuous stability.