To develop efficient heterogeneous catalyst with higher mass specific activity and stability is challenging, yet demanding nowadays due to the limited resources available for energy conversion, chemical production, and environment protection. To increase the mass-specific activity, the most used strategy is to reduce the particle size and thus to expose more surface sites. This applies particularly well for structural insensitive reactions, with cost of the increased tendency of sintering and/or disintegration of supported particles. For some of the structure sensitive reactions, the activity in term of for instance turn-over-frequency might even decrease with a reduction of the particle size. Shape-control to expose specific facets with desired activity and higher site density is a promising strategy; however, the performance of catalysts is often degraded by the strong protecting agents used to expose specific facets of catalysts. Rational design of catalysts exposing abundant active sites yet stable for a high specific activity remains a challenge.
To approach this goal, density functional theory (DFT) calculations were carried out to explore the structural sensitivity of crystal phases of transition metals on molecule activation. The great influence of crystal structure and corresponding morphology effect on formation of the various active sites with distinct intrinsic activity and density will be presented. Finally, I will present our latest development on stabilization of the supported nanoparticles, slowing down the kinetics of sintering by modulation of the metal-support interfacial interaction and particle size distribution. The influence of the reaction environment (temperature and pressure) on stability will be discussed.
Biography
Weixue Li obtained his Ph.D. from Institute of Mechanics, Chinese Academy of Sciences in 1998, and carried out his Postdoctoral research at Aarhus University, Denmark and Fritz-Haber-Institute detr MPG, Germany. He is now Professor of Department of Chemical Physics at Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China. He is an important scholar in the following dimensions of Theoretical and Computational Catalysis: Structural Sensitivity, Selectivity, and Stability of Catalysts. Professor Li was entitled as Young Leading Talent of China by MOST in 2014 and Distinguished Young Scholar of China in 2012.