Investigating the impact of catalysts on N ₂ rotational and vibrational temperatures in low pressure plasmas

Future application of plasma assisted catalysis (PAC) requires a thorough understanding of energy partitioning within the plasma-catalyst system. We have studied the impact of adding a catalyst (TiO 2 and zeolites) on the plasma energetics within an N 2 low-temperature, radio frequency (RF) plasma by measuring the vibrational and rotational temperatures of the gas-phase N 2 . The presence of either micro- or nano-structured materials (zeolite and TiO 2 substrates, respectively) within the plasma significantly decreases N 2 ( g ) vibrational temperature, suggesting these materials promote vibrational relaxation within the discharge upon interaction with a catalytic substrate. In addition to evaluating the spectroscopic characteristics of the N 2 discharge, we have assessed material morphology and chemical composition before and after plasma exposure. The porous network of both TiO 2 and zeolite substrates were maintained after plasma exposure, although small amounts of nitrogen incorporation occurred at the surface of both materials.