Promotion Effects of Nonthermal Argon Plasma Treatment and Ionic Liquids On Silica-Supported Palladium Catalysts for the Selective Hydrogenation of Acetylene To Ethylene


Kristine Jang

Document Type


Degree Name

Master of Science (MS)



Date of Award

Summer 2013


A reduction method using nonthermal argon plasma is applied to palladium catalysts with a thin layer of ionic liquid supported on silica in order to study its effects as potential catalysts for the selective hydrogenation of acetylene to ethylene. Ionic liquids [Bmim][PF6] and [Emim][BF4] are used to stabilize the palladium particles and improve interaction of acetylene gas molecules with palladium. Hydrogen to acetylene ratios that are studied include 10/1, 5/1, and 2/1. Argon plasma treatment conditions that are studied include treatment for 15 minutes, 30 minutes, 15 minutes with additional hydrogen reduction, and 30 minutes with additional hydrogen reduction. Plasma treatment alone improves the activity of the [Bmim][PF6] catalysts in comparison to the catalyst with conventional reduction. However, hydrogen reduction in addition to plasma treatment is necessary to improve the activity of the [Emim][BF4] catalysts. When comparing [Bmim][PF6] and [Emim][BF4] catalysts, reduced and reacted under the same conditions, the [Bmim][PF6] catalysts give better results, indicating better stabilization of the palladium particles by the [Bmim]+ cation and [PF6]- anion. The stabilities of the most promising catalysts are also tested to determine viability for use in industry, with results indicating argon plasma treatment improves stability. Argon plasma treatment is found to be an effective way to replace conventional hydrogen reduction procedures. The plasma reduction method is unique and can have a wide application in reducing metal precursors in the presence of ionic liquids for various catalytic reactions.


Ben Jang

Subject Categories

Chemistry | Physical Sciences and Mathematics