Evaluation of wire-mesh honeycomb containing porous Al/Al2O3 layer for catalytic combustion of ethyl acetate in air

Abstract

Wire-mesh honeycomb (WMH) catalyst is a monolith made from layers of flat and corrugated wire-meshes. To obtain an attrition-resistant washcoat on mesh surface, the mesh substrate was pre-coated with aluminum powder by electrophoretic deposition. A well-adhered aluminum layer was formed on wire-mesh surface after thermal treatment at 800 degreesC. Then, additional tuned calcination results in the formation of a thin Al2O3 layer in the outer surface of deposited aluminum particles. The Al/Al2O3-WMH was evaluated for catalytic combustion of ethyl acetate, a typical refractory volatile organic compound (VOC), after washcoating Pt/TiO2 catalyst on it. The conversion over Al/Al2O3-WMH did not decrease during the long-term operation, since the primer layer of Al/Al2O3 enhanced the catalyst adhesion. Results were compared with conventional ceramic honeycomb (CH) containing the same cell density and catalyst loading. The activity of WMH was much higher than that of CH, especially at the high-temperature ranges. It was due to the difference in external mass transfer rate between two modules. The fact was confirmed by the calculation of the external mass transfer coefficient of WMH and CH. (C) 2004 Elsevier B.V. All rights reserved.