Dielectric properties and temperature dependency of automotive catalyst coatings and substrate materials: Experimental results, influences and approximation approach

Abstract

For the radio frequency-based catalyst state monitoring of SCR catalysts, the dielectric properties of the used SCR catalyst materials are essential to design the measurement system and to adjust it to the given conditions. This work focuses on the experimental determination of the effective complex dielectric properties of zeolite coatings on cordierite substrates and the approximation of the latter to describe and transfer these systems in an easier manner. Therefore, different influences were investigated to approximate the real and the imaginary part of the complex permittivity of zeolite coatings on cordierite substrates.