Ammonia to Hydrogen Conversion in a Ferroelectric Packed-Bed Plasma Reactor: The Effect of a High-Permittivity Effective Medium Material

Abstract

Herein we report about the ammonia to hydrogen conversion induced at ambient conditions in a ferroelectric barrier discharge plasma. Decomposition yields of 40% have been found at 2.5 kV of applied voltage in a packed-bed reactor moderated with ferroelectric PZT pellets, bared and coated with layers of agglomerated Al<inf>2</inf>O<inf>3</inf> and Ru/Al<inf>2</inf>O<inf>3</inf> powders. The electrical analysis of plasma discharges, their modeling within an equivalent circuit approach and their optical emission spectroscopy characterization suggest that conventional catalytic contributions to reaction yield are negligible, even with Ru/Al<inf>2</inf>O<inf>3</inf> coated pellets for which a maximum decomposition yield was found. We propose that the main function of the Ru/Al<inf>2</inf>O<inf>3</inf> coating is to act as a high permittivity effective medium material enhancing plasma current and hence conversion yield.