Float-Stitch Precious Metal Mesh for Lower N2O Selectivity

The patent applies local quality by creating non-uniform wire distributions and varying wire diameters within the knitted mesh structure. Different regions of the mesh have different wire densities and configurations, allowing selective promotion of desired catalytic reactions in certain areas while suppressing unwanted side reactions in other areas, thereby reducing nitrous oxide emissions without compromising overall ammonia conversion efficiency

The patent employs asymmetry by using unequal wire diameters (combining fine wires with diameter 0.02-0.1 mm and coarse wires with diameter 0.1-0.5 mm) and asymmetric knitting patterns. This asymmetric structure creates diverse local catalytic environments that favor the formation of nitrogen monoxide while inhibiting nitrous oxide production, resolving the contradiction between productivity and harmful emissions

The patent segments the wire structure into two distinct categories: fine wires (0.02-0.1 mm diameter) and coarse wires (0.1-0.5 mm diameter). These segmented wire types are distributed throughout the mesh in specific patterns, with fine wires providing high surface area for catalysis and coarse wires creating larger pores that reduce N2O selectivity. This segmentation allows the mesh to achieve high ammonia conversion while suppressing harmful N2O emissions

The patent creates a composite wire structure combining different wire diameters and materials (precious metals such as platinum, palladium, rhodium, or their alloys with base metals). This composite approach allows optimization of catalytic activity through fine wires while using coarse wires to control selectivity and reduce N2O formation, effectively resolving the contradiction between productivity and harmful emissions