Abstract
A distinct advantage of cellular catalytic converters is the high specific surface area offered for catalyst distribution at low back pressure. The substrate total surface area can be used as a surrogate for other catalyst parameters in estimating overall catalytic performance. However, lacking in the literature are indications of how this surface area influence changes with aging time and temperature or with substrate material and structure. For these reasons, aging studies were carried out using ceramic and metal substrates to establish the surface area influences with time at temperatures of interest to the automotive companies. It is anticipated that the results of this study will be used to more effectively design catalysts to meet increasingly demanding durability requirements.