Progressive formation of active and stable PtZn bimetallic nanoclusters by exsolution during propane dehydrogenation

Abstract

PtZn bimetallic nanoclusters on two-dimensional (2D) molecular sieves are attractive catalysts for propane dehydrogenation (PDH) owing to the ease of molecular diffusion, resistance to deactivation by coke deposition, and electronic promotion by Zn. Here, we report the progressive formation of highly active PtZn bimetallic nanoclusters on a Pt-modified zincosilicate with 2D delaminated MWW layers (PtZn-DML) under PDH conditions. The exsolution of Zn from the zincosilicate DML framework during PDH generates highly dispersed PtZn active sites and reduces the Lewis acidity of zincosilicate DML support, resulting in a high propane conversion (40.3%) comparable to thermodynamic equilibrium as well as extraordinary stability with a low deactivation rate (kd < 0.002 h−1) up to 13.6 days.