Kinetic Parameters for the Selective Hydrogenation of Acetylene on GaPd2 and GaPd. Issue 18 (16th August 2017)

• Record Type: Journal Article
• Authors: Zimmermann, René R.; Hahn, Tobias; Reschetilowski, Wladimir; Armbrüster, Marc
• Is Part Of: Chemphyschem. Volume 18:Issue 18(2017)
• Page Start: 2517
• Page End: 2525
• Publication Date: 2017-08-16
• Subjects: gallium -- heterogeneous catalysis -- intermetallic phases -- kinetics -- palladium; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201700535
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Intermetallic GaPd2 is a highly selective and stable catalyst for the semi‐hydrogenation of acetylene. Knowledge of the underlying reaction kinetics is essential to gain a deeper understanding of the selective hydrogenation on this catalytic material. To date, there has been no experimental kinetic data published for this reaction on a well‐defined intermetallic catalyst possessing isolated active sites. Kinetic measurements are performed at 140–200 °C, revealing an apparent activation energy of 29(2) kJ mol −1 . GaPd2 is shown to be the first binary catalyst material, which shows a positive reaction order (0.89) with respect to acetylene at 200 °C. The influences on the extent of acetylene conversion, specific activity and selectivity to ethylene, ethane, and higher hydrocarbons are determined by a 2 4 factorial experiment following a design of experiments approach. Temperature and pressure have the strongest impact on these values. The results allow optimal operation for achieving high ethylene yields. A comparison of the reaction kinetics on GaPd2 with experimental results obtained for GaPd reveals different orders of reaction of H2 and C2 H2 on the two compounds. Abstract : Laws and order : The kinetics of the semi‐hydrogenation of acetylene are investigated for intermetallic compounds GaPd2 and GaPd. The apparent activation energies and orders of reaction of H2 and C2 H2 are experimentally determined. GaPd2 is shown to be the first binary catalyst material, which showed a positive reaction order (0.89) with respect to acetylene at 200 °C. A 2 4 factorial experiment is applied and allows optimization of ethylene yields.