Color center-rich γ-Al2O3 promotes propane dehydrogenation

Abstract

The PtSn/Al₂O₃ catalyst is commonly used in commercial propane dehydrogenation (PDH) processes, but it faces challenges in the deactivation and periodic regeneration due to metal aggregation and coke deposition at high temperatures. Although Al_penta³⁺ has been proven to be beneficial for enhancing catalytic stability, bottom-up synthesis protocols usually restrict their applications. Here, a facile post-treatment approach using acetic acid was applied to create color centers (electrons trapped within oxygen vacancies) on γ-Al₂O₃. Notably, the content of Al_penta³⁺ was enriched to 18.3%. Then, the pre-established PtSn clusters were loaded. The electrons facilitated the formation of ultrafine PtSn nanoparticles (∼2 nm), and the Al_penta³⁺ sites prevented the sintering of PtSn by constructing the strong Al_penta³⁺–O–Sn bonds. Furthermore, the catalytic durability of the catalyst prepared by conventional impregnation methods was remarkably extended from 186 h for the color center-free sample to 1,000 h using the HAc–Al₂O₃ support. This facile post-modification was further successfully extended to commercial Al₂O₃ pellets without altering their mechanical properties, highlighting its potential in industrial applications.