Structured reactors on a metal mesh catalyst for various applications
•The firm uniform ƞ-Al2O3 layer was deposited on the surface of the steel mesh.•Multilayer catalytic units based on metal mesh catalysts were designed and tested.•Fe-based catalysts provide high rate of NOx reduction by NH3 without N2O generation.•Addition of WO3 to Pt/Al2O3 catalyst decreases T50 in afterburning of hydrocarbons.•The mesh catalyst provides better light-off performance than the honeycomb catalyst.
The modified Bayer process allows coating of a metal mesh surface with a continuous aluminum hydroxide layer in the phase of bayerite. Subsequent calcination turns the aluminum hydroxide layer into a η-alumina layer. The method provides the uniform thickness of tens of microns for the alumina layer. Layers cracking, clogging of mesh cells are not observed. The alumina layer is formed by needle-shaped particles which coalesce to each other through common facets during crystallization. The alumina layer with high specific surface area is perfectly suitable as a support for various active components. A series of Fe-containing mesh-catalysts was tested in the NOx reduction with NH3. Addition of Ce and W to Fe increases NOx conversion significantly. The FeCeW catalyst provides almost 100% of the NOx conversion at a space velocity of 40,000 h−1 in the range of 350–500 °C with a negligible quantity of N2O. A series of Pt-containing catalysts was tested in the reaction of afterburning of hydrocarbons. Addition of tungsten oxide to the Pt/Al2O3 catalyst decreases T50 by 60 °C. An increase in the number of wire mesh leads to a drop of T50. The mesh-catalyst provides better light-off performance than the honeycomb catalyst.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (414 K)Download as PowerPoint slide
Journal: Catalysis Today - Volume 273, 15 September 2016, Pages 213–220