Single Pt Coordinated with Framework Fe in MWW-Type Ferrisilicate toward Efficient Propane Dehydrogenation

Abstract

Single atom catalysts have been widely studied due to their high metal dispersity and remarkable catalytic performance. However, stabilizing single-atom metals remains challenging because of the high surface free energy. In this work, framework Fe atom-stabilized single atom Pt were successfully confined into MWW zeolite (Pt@Fe-MWW) by a one-pot synthesis strategy. The isolated skeleton Fe served as anchoring site and promoter to stabilize the single atom Pt via Pt−O−Fe coordination as identified by the in situ CO-IR spectra and XAFS analysis, enabling Pt@ Fe-MWW with satisfied activity for the PDH reaction with trace Pt content (<0.01 wt %). A linear relationship between the quantities of Pt−O−Fe coordinated species and the propylene formation rate further confirmed the synergistic catalysis of Pt and skeleton Fe species. A recorded propylene formation rate of Pt (FR C3H6/Pt ) of 1100 mol/g Pt /h was achieved with a Pt content of 0.006 wt %. DFT calculations revealed that the formation of Pt−O−Fe species reduced the dissociation energy of the C−H bonds and facilitated the desorption of H 2 , enabling efficient propane dehydrogenation.