Anchoring atomic Pt on MFI zeolite framework Zn to construct stable and active propane dehydrogenation catalyst

Constructing an efficient Pt intermetallic alloy (IMA) species inside the zeolite intrinsic micropore is highly desired for propane dehydrogenation (PDH) process. Typical impregnation method often results in inhomogeneous dispersion of metal species on the zeolite surface. Herein, we report a strategy of constructing PtZn IMA species within the silicalite-1 (S-1) zeolite crystals by introducing Pt (NH₃)₄²⁺ ions into the ZnS-1 zeolite channels via ion-exchange. It allowed all of the Pt in the catalyst to anchored at the framework Zn and eventually transform to atomic PtZn IMA species after reduction over there. The Pt@2ZnS-1 catalyst containing 0.073 wt% Pt and 2 wt% Zn exhibited an initial propylene formation rate of 214.2 mol_C3H6∙g_Pt⁻¹∙h⁻¹ and a deactivation rate 0.00023 h⁻¹ at 550 °C in 600 h' reaction in feed gas C₃H₈/H₂/N₂ = 1/1/4 (V/V/V), and initial propylene formation rate of 301 mol_C3H6∙g_Pt⁻¹∙h⁻¹ and deactivation rate 0.00217 h⁻¹ in 100 h’ reaction in feed gas C₃H₈/N₂ = 1/4 (V/V).