Activity-Selectivity Trade-off in Propane Dehydrogenation: Pt–C Repulsion is the Essence

Abstract

While linear scaling relationships have made enormous progress in the computational design of new catalysts, the simultaneous enhancement or weakening of adsorbates for a specific reaction leads to an activity-selectivity trade-off. Focusing on the important industrial reaction, propane dehydrogenation, strategies to break linear scaling relationships have been established to maintain activity with increased selectivity. Nonetheless, elucidating the essential reason for generating the trade-off in propane dehydrogenation from electronic and geometric aspects is still elusive. Moreover, it remains uncertain whether the modified catalyst is restricted by another trade-off. This work begins by examining the effect of electronic regulation on the activity-selectivity trade-off and reveals that either too weak or too strong Pt–C repulsion is the essence of this trade-off. When geometric modulation is introduced, the alloy exhibiting similar Pt–C repulsion to Pt maintains catalytic activity with remarkably improved selectivity. However, despite establishing a better scaling relationship through geometric modulation, the activity-selectivity trade-off still exists with Pt–C repulsion as its essence.