Zr0.5Ti0.5O2(ZT) and Zr0.25Ti0.25Al0.5O2(ZTA) mixed oxides were prepared by co-precipitation method and characterized by low temperature adsorption-desorption,XRD and NH3-TPD. The activity of Pt/Zr0.5Ti0.5O2 and Pt/ Z...Zr0.5Ti0.5O2(ZT) and Zr0.25Ti0.25Al0.5O2(ZTA) mixed oxides were prepared by co-precipitation method and characterized by low temperature adsorption-desorption,XRD and NH3-TPD. The activity of Pt/Zr0.5Ti0.5O2 and Pt/ Zr0.5Ti0.5Al0.5O2 catalysts was evaluated using the simulated gases. The results show that ZTA samples exhibit higher specific surface area,larger pore volume and proper surface acidic amount and acidity in comparison with ZT. The results of the catalytic test indicate that Pt/ZT and Pt/ZTA catalysts exhibit excellent low-temperature catalytic activity and lower light-off temperatures of hydrocarbon,carbon monoxide and nitrogen oxides,especially better conversion for nitrogen oxides (NOx). The addition of Al2O3 into ZT enhanced the anti-aging property of Pt/ ZTA catalysts due to the excellent textural,structural,surface acidity and thermal stability.展开更多
Catalytic elimination of formaldehyde(HCHO) was investigated over Cu-Al_2O_3 catalyst at room temperature. The results indicated that no oxidation of HCHO into CO_2 occurs at room temperature, but the adsorption of H...Catalytic elimination of formaldehyde(HCHO) was investigated over Cu-Al_2O_3 catalyst at room temperature. The results indicated that no oxidation of HCHO into CO_2 occurs at room temperature, but the adsorption of HCHO occurs on the catalyst surface. With the increase of gas hourly space velocity(GHSV) and inlet HCHO concentration, the time to reach saturation was shortened proportionally. The results of the in situ DRIFTS, Density functional theory calculations and temperature programmed desorption(TPD) showed that HCHO was completely oxidized into HCOOH over Cu-Al_2O_3 at room temperature. With increasing the temperature in a flow of helium, HCOOH was completely decomposed into CO_2 over the catalyst surface, and the deactivated Cu-Al_2O_3 is regenerated at the same time. In addition, although Cu had no obvious influence on the adsorption of HCHO on Al_2O_3, Cu dramatically lowered the decomposition temperature of HCOOH into CO_2. It was shown that Cu-Al_2O_3 catalyst had a good ability for the removal of HCHO, and appeared to be promising for its application in destroying HCHO at room temperature.展开更多
文摘Zr0.5Ti0.5O2(ZT) and Zr0.25Ti0.25Al0.5O2(ZTA) mixed oxides were prepared by co-precipitation method and characterized by low temperature adsorption-desorption,XRD and NH3-TPD. The activity of Pt/Zr0.5Ti0.5O2 and Pt/ Zr0.5Ti0.5Al0.5O2 catalysts was evaluated using the simulated gases. The results show that ZTA samples exhibit higher specific surface area,larger pore volume and proper surface acidic amount and acidity in comparison with ZT. The results of the catalytic test indicate that Pt/ZT and Pt/ZTA catalysts exhibit excellent low-temperature catalytic activity and lower light-off temperatures of hydrocarbon,carbon monoxide and nitrogen oxides,especially better conversion for nitrogen oxides (NOx). The addition of Al2O3 into ZT enhanced the anti-aging property of Pt/ ZTA catalysts due to the excellent textural,structural,surface acidity and thermal stability.
基金The National Natural Science Foundation of China(No. 40275038)
文摘Catalytic elimination of formaldehyde(HCHO) was investigated over Cu-Al_2O_3 catalyst at room temperature. The results indicated that no oxidation of HCHO into CO_2 occurs at room temperature, but the adsorption of HCHO occurs on the catalyst surface. With the increase of gas hourly space velocity(GHSV) and inlet HCHO concentration, the time to reach saturation was shortened proportionally. The results of the in situ DRIFTS, Density functional theory calculations and temperature programmed desorption(TPD) showed that HCHO was completely oxidized into HCOOH over Cu-Al_2O_3 at room temperature. With increasing the temperature in a flow of helium, HCOOH was completely decomposed into CO_2 over the catalyst surface, and the deactivated Cu-Al_2O_3 is regenerated at the same time. In addition, although Cu had no obvious influence on the adsorption of HCHO on Al_2O_3, Cu dramatically lowered the decomposition temperature of HCOOH into CO_2. It was shown that Cu-Al_2O_3 catalyst had a good ability for the removal of HCHO, and appeared to be promising for its application in destroying HCHO at room temperature.
