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Tuning the Acidity of Pt/ CNTs Catalysts for Hydrodeoxygenation of Diphenyl Ether
Published on: August 17, 2019
Alkaline-earth-promoted Pd-Ag/Al2O3 for selective acetylene hydrogenation: green-oil mitigation, ethylene
Farnaz Rahbar Shamskar1, Sajad Mobini2, Mehran Rezaei3
1School of Chemical, Petroleum and Gas Engineering, Iran University of Science and Technology (IUST), Tehran, Iran.
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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