Activation of propane C–H and C–C bonds by a diplatinum cluster: potential energy surfaces and reaction mechanisms

Abstract

The activation mechanism of C3H8 catalyzed by the homonuclear bimetallic Pt2 cluster has been detailedly explored on the singlet and triplet potential energy surfaces at BPW91/aug-cc-pvtz, Lanl2tz level. The C–H bond cleavage channel (dehydrogenation and the release of propylene) is kinetically predominant, whereas the C–C bond cleavage channel (demethanation and the release of ethane) should be ruled out. Furthermore, the release of propylene channel is kinetically favorable, while the dehydrogenation channel is thermodynamically preferable. Besides, both the C–H cleavage intermediate (Pt2H2C3H6b) and the C–C cleavage intermediates (CH3HPt2CHCH3 and CH3PtPtHC2H4) are thermodynamically preferred. The C–H cleavage intermediate (Pt2H2C3H6b) is kinetically favored, while the C–C cleavage intermediates (CH3HPt2CHCH3 and CH3PtPtHC2H4) are kinetically hindered. The homonuclear bimetallic Pt2 cluster toward propane exhibits higher reactivity than the Pt atom, which is in good agreement with the experimental observation.