A series of catalysts of Mn/USY and Mn-Fe/USY prepared by impregnation were studied for low-temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of excess of oxygen. It was found that the a...A series of catalysts of Mn/USY and Mn-Fe/USY prepared by impregnation were studied for low-temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of excess of oxygen. It was found that the addition of Fe enhanced the catalytic performance at low-temperature. Mn-Fe/USY catalyst yielded nearly 100% NO conversion in a range of temperature from 423 to 573 K at a space velocity of 36 000 cm3g^-1·h^-1. Coexistence of manganese and iron oxides enhanced the dispersion of the supported oxides, no visible phase of the oxides can be observed on catalyst. The addition of Fe enhanced the number and strength of the Bronsted and Lewis acid sites on the surface of the catalyst, which might promote the absorption of NH3 to form active intermediate and enhance the catalytic performance at low-temperature.展开更多
Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios (Ce-Mn/GF) were prepared by an impregnation method and tested for low-temperature (80 180 ℃) selective cataly...Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios (Ce-Mn/GF) were prepared by an impregnation method and tested for low-temperature (80 180 ℃) selective catalytic reduction (SCR) of NO with ammonia. This brand-new technology could remove NO and particles matter from coal-fired flue gas. The surface properties of the catalysts were examined by means of Bmnauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The experimental results showed that the catalyst with a Ce/Mn molar ratio of 0.2 obtained high activity of 87.4% NO conversion at 150 ℃ under a high space velocity of 50000 h1. Deactivation poisoned by SO2 still occurred, but the Ce-Mn/GF(0.2) catalyst performed desirable tolerance to SO2 with decreasing 50% in 40 min and then maintaining at about 30% NO conversion. Characterization results indicated that the excellent low-temperature catalytic activity was related to the high specific surface area, pore structure, and amorphous phase.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No. 20437010) the Chinese Postdoctoral Science Foundation (No. 2005037058).
文摘A series of catalysts of Mn/USY and Mn-Fe/USY prepared by impregnation were studied for low-temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of excess of oxygen. It was found that the addition of Fe enhanced the catalytic performance at low-temperature. Mn-Fe/USY catalyst yielded nearly 100% NO conversion in a range of temperature from 423 to 573 K at a space velocity of 36 000 cm3g^-1·h^-1. Coexistence of manganese and iron oxides enhanced the dispersion of the supported oxides, no visible phase of the oxides can be observed on catalyst. The addition of Fe enhanced the number and strength of the Bronsted and Lewis acid sites on the surface of the catalyst, which might promote the absorption of NH3 to form active intermediate and enhance the catalytic performance at low-temperature.
基金Project supported by the National High Technology Research and Development Program of China(863 Program)(2008AA05Z305)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(201109)+2 种基金the Master Dissertation Innovation Funded Projects(EG2013015)the Fundamental Research Funds for the Central Universities Special Fund Project(11D11315)Program of Shanghai Subject Chief Scientist(14XD1424700)
文摘Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios (Ce-Mn/GF) were prepared by an impregnation method and tested for low-temperature (80 180 ℃) selective catalytic reduction (SCR) of NO with ammonia. This brand-new technology could remove NO and particles matter from coal-fired flue gas. The surface properties of the catalysts were examined by means of Bmnauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The experimental results showed that the catalyst with a Ce/Mn molar ratio of 0.2 obtained high activity of 87.4% NO conversion at 150 ℃ under a high space velocity of 50000 h1. Deactivation poisoned by SO2 still occurred, but the Ce-Mn/GF(0.2) catalyst performed desirable tolerance to SO2 with decreasing 50% in 40 min and then maintaining at about 30% NO conversion. Characterization results indicated that the excellent low-temperature catalytic activity was related to the high specific surface area, pore structure, and amorphous phase.