Intensification of a hydrogenation catalyst activity by nanosecond pulsed discharge treatment

• Published in: Plasma processes and polymers Vol. 15; no. 8
• Main Authors: Delikonstantis, Evangelos, Scapinello, Marco, Sklari, Stella D., Stefanidis, Georgios D.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.08.2018
• Subjects: Acetylene; Catalysis; Catalysts; catalytic hydrogenation; Chemisorption; Conversion; Discharge; ethylene; Hydrogenation; Inductively coupled plasma mass spectrometry; Metal surfaces; nanosecond pulsed discharge; Organic chemistry; Palladium; Phase transitions; Plasma; plasma‐catalyst interaction; Surface area
• ISSN: 1612-8850; 1612-8869
• DOI: 10.1002/ppap.201800065

In this work, we report on a Johnson Matthey‐developed palladium (Pd)‐based catalyst activity enhancement using nanosecond pulsed discharge treatment. The impact of treatment energy via pulse voltage, pulse frequency, and treatment time individual variation on acetylene‐to‐ethylene hydrogenation reaction performance is investigated. Up to 11.2% increase in C2H2 conversion is attained after plasma treatment at specific treatment energy of 5340 J gcat−1, while C2H4 selectivity remains constant. To elucidate the effect of plasma on catalyst activity, characterization with SEM, BET, CO chemisorption, ICP‐MS, and XRD is carried out. C2H2 conversion increase is due to the higher active metal surface area attained after the plasma treatment. Other than the improved Pd surface area, not significant increase in specific surface area is observed, while even at high energy inputs no catalyst destruction occurs, as neither metal losses, nor phase changes are induced during plasma treatment. Plasma active species can interact with catalytic surfaces inducing physical and chemical properties modifications and intensification of the heterogeneous catalyst performance. Herein, a Pd‐based catalyst is treated by argon plasma in a co‐axial (DBD) reactor, at different treatment conditions, powered by a nanosecond pulsed power supply. The catalyst performance is tested before and after plasma pretreatment in a tubular reactor under conventional furnace heating.