Propane dehydrogenation by atomically thin platinum layer on pristine two-dimensional MXenes

Abstract

Contradiction between catalytic activity and coking-resistivity of propane dehydrogenation (PDH) has been a major concern. Here, the potential of using pristine MXenes as supports in stabilizing Pt atomically thin noble metal layers (ATNLs) for catalyzing PDH was evaluated by first-principles calculations and microkinetic simulations. Various electronic structure analyses demonstrated that the MXenes could stabilize Pt ATNLs via strong metal–metal bonding, leading to expanded Pt lattice constants, and accumulated electron density on Pt. Consequently, MXene-supported Pt ATNLs favored propylene desorption over further dehydrogenation, contributing to higher propylene selectivity and anti-coking ability. In particular, the Pt ATNLs on Mo2C and W2C showed comparable activity with the pure Pt (111) surface, but might improve the anti-coking ability by 4 to 6 orders of magnitude. Finally, propylene binding strength, which could be explained by the d-band theory, was identified as an effective indicator in determining PDH reactivity and anti-coking ability.