Details

Autor(en) / Beteiligte

• Potter, M. E
• McColl, K
• Corà, F
• Levy, A. B
• Raja, R

Titel

Theoretical insights into the nature of synergistic enhancement in bimetallic CoTiAlPO-5 catalysts for ammonia activationElectronic supplementary information (ESI) available: This includes geometric information on monometallic and bimetallic systems. Coordination geometries of ammonia-bound species, energy profile of non-catalytic ammonia activation, Γ-point phonon modes for the transition states, further figures on the evolution of bond lengths and spin for the radical formation and radical sta

Erscheinungsjahr

2017-08

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Bimetallic catalytic synergy, the concurrent action of two different metal ions in the same material, has resulted in improved efficiency in many catalytic systems and for a range of chemical processes. Via a computational mechanistic study, we investigate the catalytic benefits of the bimetallic CoTiAlPO-5 material in comparison to the monometallic CoAlPO-5 system, on the activation of NH 3 . The presence of Ti in a framework site adjacent to Co stabilises the Co( ii ) oxidation state, and increases the Co( iii )/Co( ii ) reduction potential. We show that this change lowers the activation barrier for the homolytic H extraction from NH 3 by Co( iii ), from 162 kJ mol −1 in the monometallic CoAlPO-5 catalyst to 140 kJ mol −1 in the bimetallic CoTiAlPO-5 (175 and 111 kJ mol −1 respectively when considering both dispersion and free energy corrections). Elucidation of mechanistic details through computational studies can make significant contributions to the rational design of catalytic materials. Bimetallic catalytic synergy, the concurrent action of two different metal ions in the same material, has resulted in improved efficiency in many catalytic systems and for a range of chemical processes.