Catalytic performance of oxygenated acid sites on activated carbon generated by non-isothermal plasma

Oxygenated surface sites on Activated Carbon (AC) exhibit low acid strength but are still useful to catalyze reactions of industrial interest. A series of AC-based acid catalysts was prepared by modifying a basic-character AC with an O 2 plasma using a rotary dielectric barrier discharge reactor, to get further insight of the catalytic potential of the oxygenated acid sites generated by this technique. The O 2 plasma treatment time (t PO2 ) had an important effect on the catalysts morphology and the oxygenated surface sites distribution. The non-isothermal O 2 plasma configuration used to oxidize AC was a suitable alternative to generate strong and weak carboxylic acids sites that were active and selective for the gas phase dehydration of isopropanol to propene, being the weak carboxylic acid sites less active but more stable. A maximum activity (Turnover frequency) was found as a function of t PO2, which was explained in terms of the balance between the density and the strength of oxygenated acid sites. The approach used in this study shows the benefits and limitations of non-isothermal plasma technology to generate oxygenated acid sites on AC-based catalysts.