Sm2O3-LaF3 and BaF2 promoted Sm2O3W3 catalysts shown good catalytic performance for the Oxidative Dehydrogenation of Ethane(ODE). XRD and XPS characterizations of the catalysts show the structure defects, which may be...Sm2O3-LaF3 and BaF2 promoted Sm2O3W3 catalysts shown good catalytic performance for the Oxidative Dehydrogenation of Ethane(ODE). XRD and XPS characterizations of the catalysts show the structure defects, which may be produced by the partial exchange of anions and cations,enhance the electron donating ability and increase the surface absorbed oxygen concentration thus should be favorable to improve the catalytic activity. However, the higher concentration of surface adsorbed oxygen is unfavorable for the ethene selectivity.展开更多
order to assess the promotional effects of La3+ on CO hydrogenation of Co/SiO2 catalyst, solvated metal atom impregnation (SMAI) method was used to prepare unpromoted 10% (mass fraction) Co/SiO2 and a series of La3+-p...order to assess the promotional effects of La3+ on CO hydrogenation of Co/SiO2 catalyst, solvated metal atom impregnation (SMAI) method was used to prepare unpromoted 10% (mass fraction) Co/SiO2 and a series of La3+-promoted 10% (mass fraction) Co/SiO2 catalyst with different La/Co atomic ratios (0.1, 0.3, 0.5). X-ray diffraction (XRD), and CO chemisorption measurements show that the cobalt particle size decreases as the La/Co ratios increase. X-ray photoelectron spectrescopy indicates that cobalt is in zero-valent state for all the samples. Catalytic test shows that the catalytic activity of La3+-promoted Co/SiO2 in CO hydrogenation is higher than that of unpromoted Co/SiO2, and enhances with the La/Co ratios increase. La3+ promotion also causes the enhanced selectivity of Co/SiO2 catalyst for higher hydrocarbon products.展开更多
采用浸渍法制备出γ-Al2O3、SiO2和γ-Al2O3.SiO2负载的Ni-La催化剂,用XRD、TPR、XPS、H2-TPD、NH3-TPD和TG等手段对催化剂进行了表征,结果表明:这3种负载型催化剂中的活性组分Ni的分散度较高,La3+氧化物高度分散于载体表面.在温度为40...采用浸渍法制备出γ-Al2O3、SiO2和γ-Al2O3.SiO2负载的Ni-La催化剂,用XRD、TPR、XPS、H2-TPD、NH3-TPD和TG等手段对催化剂进行了表征,结果表明:这3种负载型催化剂中的活性组分Ni的分散度较高,La3+氧化物高度分散于载体表面.在温度为400℃、水醇比为4.0和液体空速为8.0 mL h-1gc-at1的条件下,催化剂进行稳定性测试,结果表明:γ-Al2O3.SiO2负载的Ni-La催化剂在整个100 h稳定性测试过程中,氢气的选择性保持在67.0%左右,且稳定性良好.对经过稳定性测试后的Ni-La催化剂进行热重分析,发现γ-Al2O3.SiO2负载的Ni-La催化剂具有较少的积碳量,仅仅是0.86 g C.gc-at1,其中石墨碳占42.81%.展开更多
文摘Sm2O3-LaF3 and BaF2 promoted Sm2O3W3 catalysts shown good catalytic performance for the Oxidative Dehydrogenation of Ethane(ODE). XRD and XPS characterizations of the catalysts show the structure defects, which may be produced by the partial exchange of anions and cations,enhance the electron donating ability and increase the surface absorbed oxygen concentration thus should be favorable to improve the catalytic activity. However, the higher concentration of surface adsorbed oxygen is unfavorable for the ethene selectivity.
文摘order to assess the promotional effects of La3+ on CO hydrogenation of Co/SiO2 catalyst, solvated metal atom impregnation (SMAI) method was used to prepare unpromoted 10% (mass fraction) Co/SiO2 and a series of La3+-promoted 10% (mass fraction) Co/SiO2 catalyst with different La/Co atomic ratios (0.1, 0.3, 0.5). X-ray diffraction (XRD), and CO chemisorption measurements show that the cobalt particle size decreases as the La/Co ratios increase. X-ray photoelectron spectrescopy indicates that cobalt is in zero-valent state for all the samples. Catalytic test shows that the catalytic activity of La3+-promoted Co/SiO2 in CO hydrogenation is higher than that of unpromoted Co/SiO2, and enhances with the La/Co ratios increase. La3+ promotion also causes the enhanced selectivity of Co/SiO2 catalyst for higher hydrocarbon products.
文摘采用浸渍法制备出γ-Al2O3、SiO2和γ-Al2O3.SiO2负载的Ni-La催化剂,用XRD、TPR、XPS、H2-TPD、NH3-TPD和TG等手段对催化剂进行了表征,结果表明:这3种负载型催化剂中的活性组分Ni的分散度较高,La3+氧化物高度分散于载体表面.在温度为400℃、水醇比为4.0和液体空速为8.0 mL h-1gc-at1的条件下,催化剂进行稳定性测试,结果表明:γ-Al2O3.SiO2负载的Ni-La催化剂在整个100 h稳定性测试过程中,氢气的选择性保持在67.0%左右,且稳定性良好.对经过稳定性测试后的Ni-La催化剂进行热重分析,发现γ-Al2O3.SiO2负载的Ni-La催化剂具有较少的积碳量,仅仅是0.86 g C.gc-at1,其中石墨碳占42.81%.
