Low temperature catalytic oxidation of nitric oxide over the Mn–CoOx catalyst modified by nonthermal plasma

• The activity of NTP-treated catalysts improved significantly for NO oxidation.
• Plasma treatment varied the surface area and pore volume of catalyst significantly.
• The chemisorbed oxygen and surface specie valence were varied significantly.
• Synergetic catalytic effect between Co and Mn with possible mechanism was proposed.

Nonthermal plasma (NTP) treatment was investigated to modify the Mn–CoOx catalyst for the low-temperature oxidation of nitric oxide. The catalysts were characterized by XRD, BET, TGA and XPS techniques. The results showed that the activity of NTP-treated catalysts improved significantly, and that NTP treatment has the advantage of changing the structural and morphological properties (higher surface areas and pore volume) and varying the relative surface concentration and oxidation states of surface species over catalysts. High surface areas and pore volume, high concentration of chemisorbed oxygen, Mn4 + and Co2 +, and the efficient synergetic catalytic effect between Co and Mn ions were thought to be the main reasons for the high activity of NTP-treated catalysts.

The activity of catalysts treated by NTP improved significantly due to high surface areas and pore volume, high concentration of chemisorbed oxygen, high Mn4 + and Co2 +, and the efficient synergetic catalytic effect (electron transfer) between Co and Mn.Figure optionsDownload as PowerPoint slide