Wire-mesh honeycomb catalysts for selective catalytic reduction of NO with NH3

Abstract

Both flat and corrugated wire mesh sheets were coated with aluminum powder by using electrophoretic deposition (EPD) method. Controlled thermal sintering of coated samples yielded uniform porous aluminum layer with a thickness of 100 μm that was attached firmly on the wire meshes. Subsequent controlled calcination formed a finite thickness of Al2O3 layer on the outer surface of each deposited aluminum particles, which resulted in the formation of Al2O3/Al double-layered composite particles that were attached firmly on the wire surface to form a certain thickness of porous layer. A rectangular-shaped wire-mesh honeycomb (WMH) module with triangular-shaped channels was manufactured by packing alternately the flat sheet and corrugated sheet of the Al2O3/Al-coated wire meshes. This WMH was further coated with V2O5-MoO3-WO3 catalyst by wash-coating method to be applied for the selective catalytic reduction (SCR) of NO with NH3. With an optimized catalyst loading of 16 wt%, WMH catalyst module shows more than 90% NO conversion at 240 °C and almost complete NO conversion at temperatures higher than 300 °C at GHSV 5,000 h−1. When compared with conventional ceramic honeycomb catalyst, WMH catalyst gives NO conversion higher by 20% due to reduced mass transfer resistance by the existence of three dimensional opening holes in WMH.