Study on Coating Method of Ag/Al2O3 Catalyst System on the Stainless Steel

A coating process of Ag/Al2O3 catalyst powder on an aluminum-free stainless steel has been investigated for NOx reduction. The stainless steel SUS304 was coated with γ-Al2O3 powder or Ag/Al2O3 catalyst powder by dip coating method using aluminum nitrate as a binder and heated in air. The heating temperature was determined by TG-DTA analysis and the heating period, the concentrations of the binder and the coating powder as well as the number of coats were changed to optimize preparation conditions. As a result, a coating layer with a thickness of approximately 4-5μm was formed on SUS304 without exfoliation. A catalytic ability of the coated sample for NOx reduction was highly enhanced as compared with that coating the catalyst powder without the binder on γ-Al2O3 coating layer.