Co sub(3)O sub(4) based catalysts for NO oxidation and NO sub(x) reduction in fast SCR process

• Published in: Applied catalysis. B, Environmental Vol. 78; no. 3-4; pp. 267 - 274
• Main Authors: Irfan, Muhammad Faisal, Goo, Jeong Hoi, Kim, Sang Done
• Format: Journal Article
• Language: English
• Published: 01.02.2008
• Subjects: Air pollution control; Catalysis; Catalysts; low temperature; Oxidation; Q1; Sulfur dioxide; Temperature
• ISSN: 0926-3373
• DOI: 10.1016/j.apcatb.2007.09.029

Reaction activities of several developed catalysts for NO oxidation and NO sub(x) (NO + NO sub(2)) reduction have been determined in a fixed bed differential reactor. Among all the catalysts tested, Co sub(3)O sub(4) based catalysts are the most active ones for both NO oxidation and NO sub(x) reduction reactions even at high space velocity (SV) and low temperature in the fast selective catalytic reduction (SCR) process. Over Co sub(3)O sub(4) catalyst, the effects of calcination temperatures, SO sub(2) concentration, optimum SV for 50% conversion of NO to NO sub(2) were determined. Also, Co sub(3)O sub(4) based catalysts (Co sub(3)O sub(4)-WO sub(3)) exhibit significantly higher conversion than all the developed DeNO sub(x) catalysts (supported/unsupported) having maximum conversion of NO sub(x) even at lower temperature and higher SV since the mixed oxide Co-W nanocomposite is formed. In case of the fast SCR, N sub(2)O formation over Co sub(3)O sub(4)-WO sub(3) catalyst is far less than that over the other catalysts but the standard SCR produces high concentration of N sub(2)O over all the catalysts. The effect of SO sub(2) concentration on NO sub(x) reduction is found to be almost negligible may be due to the presence of WO sub(3) that resists SO sub(2) oxidation.