Spectroscopic diagnostics of plasma-assisted catalytic systems for NO removal from NO/N2/O2/C2H4 mixtures

Inductively coupled plasma was used to study the removal of NOx from NO/N2/O2/C2H4 mixtures in Co-ZSM-5 packed radio frequency (RF) plasma. Laser-induced fluorescence (LIF), optical emission spectroscopy (OES), and mass spectroscopy temperature programmed desorption (MS-TPD) were applied to investigate the effects of the plasmas parameters, such as discharge power (Pdis), discharge pressure (p) on the concentration of reactive species in the gas phase or stable surface species formed over catalyst active sites. Rotational and vibrational temperatures of N2 in Co-ZSM-5 packed and no packed RF plasmas were also analyzed. Possible mechanism for the NOx-selective catalytic reduction (SCR) with C2H4 over Co-ZSM-5 packed RF plasmas was addressed.