Highly Stable Propane Dehydrogenation on a Self-Supporting Single-Component Zn₂SiO₄ Catalyst

Current industrial propane dehydrogenation (PDH) processes predominantly use either toxic Cr-based or expensive Pt-based catalysts, necessitating urgent exploration for alternatives. Herein, we present Zn₂SiO₄, an easily prepared, cost-effective material, as a highly efficient and stable catalyst for PDH. Uniquely, Zn₂SiO₄ nanocrystals do not require dispersion on support materials, commonly needed for catalytic active oxide clusters, but function as a self-supporting catalyst instead. During the reaction's induction period, surface Zn species on the Zn₂SiO₄ crystal reduce to coordinately unsaturated ZnO_x single sites, serving as highly active catalytic centers. The Zn₂SiO₄ catalyst demonstrates a stable performance over 200 hours of PDH operation at 550 °C. We further find that introducing a minuscule amount of CO₂ into the propane feed significantly extends the catalyst lifespan to over 2000 hours. This enhancement arises from the special role of CO₂ in facilitating the removal of strongly adsorbed H*, preventing the complete reduction of ZnO_x. After prolonged reaction, the activity of Zn₂SiO₄ can be fully restored by etching the surface layer to expose fresh Zn species, available throughout the crystals. The combination of CO₂introduction and catalytic site regeneration strategies is expected to enable a year-long PDH operation using a single batch of Zn₂SiO₄ catalyst.