Catalytic reduction of NO by CO with Cu-based and Mn-based catalysts

Abstract

• Cu-Ce-Fe-Co/TiO 2 shows the best catalytic performance for the reduction of NO with CO process among all the Cu-based and Mn-based catalysts. • Cu-Ce-Fe-Co/TiO 2 possesses good reducibility and more oxygen vacancies, resulting in high activity for the reduction of NO by CO process. • Cu-Ce-Fe-Co/TiO 2 has lower activation energy (54.2 kJ/mol) for the reduction of NO by CO process if compared with Mn-Ce-Fe-Co/TiO 2 . • Catalytic performance could be enhanced as Cu-Ce-Fe-Co is loaded on activated carbon (AC) to form Cu-Ce-Fe-Co/AC. Various Cu-based and Mn-based catalysts are prepared and evaluated for the reduction of NO with CO process. Cu-Ce-Fe-Co/TiO 2 and Mn-Ce-Fe-Co/TiO 2 show the best catalytic performance for the reduction of NO with CO process among Cu-based and Mn-based catalysts, respectively. The highest conversions of NO and CO achieved with Cu-Ce-Fe-Co/TiO 2 reach 100% and 79%, respectively, with the operating temperature of 250 ℃, while 100% and 70% are achieved with Mn-Ce-Fe-Co/TiO 2 for the gas streams containing 200 ppm NO and 200 ppm CO. The results reveal that both modified catalysts (e.g., Cu-Ce-Fe-Co/TiO 2 and Mn-Ce-Fe-Co/TiO 2 ) have good activities for CO + NO reaction. Overall, Cu-Ce-Fe-Co/TiO 2 has better tolerance for O 2 , SO 2 and H 2 O (g) than Mn-Ce-Fe-Co/TiO 2 . Good catalytic performance of Cu-Ce-Fe-Co/TiO 2 toward NO reduction is attributed to its good surface properties, i.e., reducibility, oxygen mobility and more oxygen vacancies. Additionally, the apparent activation energy is calculated as 54.2 kJ/mol is calculated using Mars-Van Krevelen model for reduction of NO with CO process with Cu-Ce-Fe-Co/TiO 2 as catalyst. Further, active component Cu-Ce-Fe-Co is loaded on activated carbon (AC) to form Cu-Ce-Fe-Co/AC, which is applied as catalyst for durability test. The results indicate that NO conversion achieved with Cu-Ce-Fe-Co/AC maintains at 100% during 240 min operation period, even in the simultaneous presence of O 2 , H 2 O (g) and SO 2 . Overall, this study demonstrates that Cu-based catalyst is promising for the reduction of NO with CO process.