Bimetallic catalysts have attracted increasing attention in propane dehydrogenation (PDH) due to the synergistic effect of metal species and considerably improved catalytic performance, but they often suffer from severe sintering and poor stability. Here, well-dispersed and ultrasmall PtZn bimetallic nanoclusters encapsulated in silicalite-1 (S-1) zeolites (named PtZn@S-1) are prepared via a facile in situ synthesis strategy. It is indicated that the PtZn bimetallic nanoclusters with ultrasmall size are homogeneously dispersed within the channels of S-1 zeolites. The 0.3Pt0.5Zn@S-1 catalyst shows excellent catalytic performance in PDH with a propane conversion of 45.3% and a propylene selectivity of >99%, and no visible sintering of PtZn bimetallic nanoclusters is observed in the long-term PDH reaction at 550 degrees C. The excellent catalytic properties and high stability of the ultrasmall bimetallic nanoclusters confined in zeolites create new prospects for PDH. (C) 2020 Elsevier Inc. All rights reserved.