Abstract
Removing trace acetylene from ethylene streams is critical to protect Ziegler–Natta polymerization. Eggshell Pd–Ag/θ-Al2O3 spheres (0.03 wt% Pd, 0.13 wt% Ag) were promoted with 1 wt% alkaline-earth additives to suppress green oil and improve ethylene selectivity. XRD, N2 physisorption, H2-TPR, NH3/CO2-TPD, TPO, SEM–EDS, and ICP-OES established structure-property links. Fixed-bed tests (10 bar, 40–60 °C) after H2 prereduction showed promoter-stabilized θ-Al2O3, higher surface area and mesoporosity and stronger metal-support interactions. All promoted catalysts achieved ≳ 96% acetylene conversion with higher ethylene selectivity and reduced carbon deposition. A possible contribution from hydrogen spillover is discussed qualitatively based on indirect evidence.
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The datasets used and analyzed during the current study are available from the corresponding author upon reasonable request.
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Giving access to the facilities from the Iran National Science Foundation (INSF) under the grant number of 4031093 to perform this project is kindly appreciated and acknowledged.
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Contributions S.M.T.: Conceptualization, methodology, validation, investigation, writing—original draft. S.M.A.: Supervision, validation, funding, writing—review and editing. M.R.: Supervision, validation, funding, writing—review and editing.
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Rahbar Shamskar, F., Mobini, S. & Rezaei, M. Alkaline-earth-promoted Pd–Ag/Al2O3 for selective acetylene hydrogenation: green-oil mitigation, ethylene selectivity, and implications for hydrogen spillover. Sci Rep (2026). https://doi.org/10.1038/s41598-026-46044-5
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DOI: https://doi.org/10.1038/s41598-026-46044-5
