10.1021/om300562d
The research investigates the dehydrogenation of ammonia?borane (AB) catalyzed by Shvo’s cyclopentadienone-ligated ruthenium complex. The study aims to elucidate the mechanism of catalyst deactivation and the transition from fast to slow catalysis, which is crucial for developing a practical hydrogen storage system using AB. The researchers propose a three-stage model: catalyst initiation, fast catalysis, and slow catalysis. They identify borazine-mediated hydroboration of the ruthenium species as the primary cause of catalyst deactivation, leading to a change in the reaction rate law and the catalyst's apparent resting state. Key chemicals used in the study include ammonia?borane (AB), Shvo’s catalyst (12), borazine, and ethanol. The findings suggest that designing a second-generation catalyst that avoids oxygen-based proton acceptance could mitigate deactivation issues, paving the way for more efficient hydrogen storage solutions.
10.1002/chem.201003543
The research investigates the catalytic hydrolysis of ammonia borane (H3N-BH3) using rhodium-based aminophosphine complexes to generate hydrogen (H2) under mild conditions. The purpose is to develop an efficient and controlled method for hydrogen generation, which is crucial for applications in fuel cells and portable electronic devices. The study focuses on the performance of rhodium aminophosphine complexes, such as [RhCl(cod){P(NC5H10)3-n(C6H11)n}], which act as precursors to rhodium nanoparticles and catalyze the sequential dehydrogenation and hydrolysis of ammonia borane in THF/H2O mixtures, releasing up to 3.0 equivalents of H2. Key findings include the significant influence of ligand modifications and solvent composition on the catalytic activity and product formation. For instance, the presence of water in the reaction mixture leads to the formation of NH3 and B(OH)3, while anhydrous conditions result in the formation of borazine and polyborazylene. The study concludes that these aminophosphine-based rhodium complexes are highly active and tunable systems for hydrogen generation from ammonia borane, with potential for practical applications in hydrogen storage and fuel cell technology.
