Plasma-assisted activation of supported Au and Pd catalysts for CO oxidation

A nonthermal atmospheric pressure helium plasma was used for catalyst activation. The CO oxidation activity of alumina-supported Au and Pd catalyst was monitored using a gas chromatograph before and after plasma treatment. Catalysts were prepared by incipient wetness impregnation of Au and Pd salts on alumina. The plasma-treated Au catalyst converted 78% CO to CO₂ as compared to 45% in the case of untreated catalyst at room temperature. Similarly, plasma-treated Pd catalysts demonstrated improved performance at 100°C and 150°C. At 100°C, 16% conversion was achieved with the plasma-treated catalyst whereas there was no conversion with untreated catalyst. The conversion increased to 82% as compared to 44% for the untreated sample at 150°C. At 200°C both untreated as well as plasma-treated samples achieved nearly 100% conversion.