| 研究実績の概要 |
I successfully applied a catalyst design concept based on a pseudo-binary alloy for the fine-tuning of the active property. A series of (Ni1－xCux)3Ga/TiO2 catalysts exhibiting L12-type pseudo-binary alloy structures with various Cu contents were prepared for active site tuning. The optimal catalyst, (Ni0.8Cu0.2)3Ga/TiO2, exhibited outstandingly high catalytic activity among reported 3d transition metal-based systems and excellent ethylene selectivity (96%) and long-term stability (100 h) with near full conversion even at 150°C. It revealed that Ni2Cu hollow sites on the (111) surface weakened the strong adsorption of acetylene and vinyl adsorbate, which significantly accelerated the hydrogenation process and inhibited undesired ethane formation.
|
| 今後の研究の推進方策 |
As we all know, some 3d-transition metals are potential candidates for CO2 hydrogenation but they are essentially immiscible at equilibrium due to the positive enthalpies of formation of their solid solution alloys. However, this can be obtained by HEA because the number of elements increase. Therefore, the value of entropy increases. Then, the Gibbs free energy decrease, promoting the formation of solid solution. Besides, high mixing entropy leads to enhanced stability at high temperature.
|
