Elucidating High-Efficiency Guidance Design and Performance Optimization of Pt-Based Catalysts for Propane Dehydrogenation

Abstract

Maintaining high dispersion of Pt in catalysts remains a significant challenge due to Pt migration and aggregation. Addressing this gap is critical for advancing the design of catalysts with enhanced performance and stability, particularly in applications requiring strong metal–support interactions. Here, we introduce a novel catalyst preparation method that employs an ethylenediaminetetraacetic acid disodium salt (EDTA) as a directing agent to stabilize Pt on an Al₂O₃ support promoted by Sn. Leveraging the ability of EDTA to selectively bind Pt and Sn, we synthesized a highly dispersed Pt–Sn–Al₂O₃ dehydrogenation catalyst. First-principles calculations based on density functional theory confirmed that the carbonyl and hydroxyl oxygen atoms in EDTA preferentially bond with Sn in the Al₂O₃ support, facilitating precise Pt anchoring. Experimental results further validated these findings, showing that EDTA-guided synthesis enhanced the formation of Pt–Sn–Al₂O₃ active sites and led to stronger metal–support interactions, resulting in uniform Pt particle distribution and improved catalyst stability. This approach not only increased propylene selectivity from about 85% to 93% but also significantly reduced methane byproduct formation. These findings demonstrate that the introduction of EDTA as a directing agent can effectively address Pt aggregation issues, offering a promising strategy for designing more efficient and stable catalysts for industrial dehydrogenation processes.