Positive effects of a halloysite-supported Cu/Co catalyst fabricated by a urea-driven deposition precipitation method on the CO-SCR reaction and SO2 poisoning

Cu/Co catalysts were prepared on halloysite nanotube supports by a urea-driven deposition-precipitation method for CO oxidation and the selective catalytic reduction of NO (CO-SCR). First, the Cu/NH3 molar ratio was investigated to identify the copper species in the catalysts and evaluate the CO oxidation ability. According to the results, the relative amount of [Cu(NH3)(4)](2+) species increases with increasing urea concentration, and the Cu/halloysite-1/6 catalyst exhibits strong metal-support interactions and has well-dispersed CuO particles at a Cu/NH3 molar ratio of 1/6. Moreover, the interaction between [Cu(NH3)(4)](2+) and halloysite is enhanced by electrostatic effects, which helps suppress particle migration and sintering. In addition, the promotion effects of cobalt on CuCo/HNT in the NO + CO and NO + CO + SO2 reactions were also examined. The results suggest that a strong synergistic effect between Cu and Co in the catalyst can improve their reducibilities; thus, the CO and NO conversions are greatly increased by 50% at 400 degrees C. Moreover, CuCo/HNT exhibits higher SO2 resistance than Cu/HNT-1/6, and it can maintain 30% CO and NO conversion after SO2 poisoning.

Automated summary

Cu/Co catalysts prepared on halloysite nanotube supports by a urea-driven deposition-precipitation method show strong performance in CO oxidation and the selective catalytic reduction of NO, with the ability to suppress particle migration and sintering. A strong synergistic effect between Cu and Co in the catalyst improves reducibility and conversion rates, leading to significant increases in CO and NO conversions.