In this paper, the properties of carbon deposited on hexaaluminateLaNiAl_(11)O_(19) catalyst were characterized by X-ray photoelectron spectroscopy (XPS), and in themeantime, the amount of carbon deposited on the cata...In this paper, the properties of carbon deposited on hexaaluminateLaNiAl_(11)O_(19) catalyst were characterized by X-ray photoelectron spectroscopy (XPS), and in themeantime, the amount of carbon deposited on the catalyst, after both CH_4 decomposition and CO_2reforming of CH_4, was determined by means of thermogravimetric analysis (TGA), respectively. Therates of carbon deposited on the catalyst were also investigated and the apparent kinetic equationof CO_2 reforming of CH_4: ν_c = kp^(0.72)(CH_4)·p^(-0.55)(CO_2), was established by analyzing therelation between the rates of deposited carbon and the pressure ratio of CH_4 and CO_2.展开更多
A new type of the catalyst, LaNiAl11O19 for the methane reforming with carbondioxide was synthesized and evaluated. LaNiAl11O19 has a hexaaluminate structure and cankeep large surface and heat resistance against sinte...A new type of the catalyst, LaNiAl11O19 for the methane reforming with carbondioxide was synthesized and evaluated. LaNiAl11O19 has a hexaaluminate structure and cankeep large surface and heat resistance against sintering at high reaction temperature. Ascompared with La2O3-Ni/SrAl12O19, in the CH4+CO2 reaction, LaNiAl11O19 catalyst displaysa higher catalytic activity, lower coking amount and excellent sintering resistance of Niparticle, due to its stable structure.展开更多
In this paper, a series of hexaaluminate oxides, LaMAl 11 O 19-δ (M=Fe, Co, Ni, Mn and Cu), were prepared using transition metals M to substitute Al in the hexaaluminate lattices. XRD analyses indicated that the seri...In this paper, a series of hexaaluminate oxides, LaMAl 11 O 19-δ (M=Fe, Co, Ni, Mn and Cu), were prepared using transition metals M to substitute Al in the hexaaluminate lattices. XRD analyses indicated that the series of hexaaluminates had almost the same magnetoplumbite crystal structure, however, they exhibted different reducibility and catalytic activities for CO 2 reforming of methane to synthesis gas. Among the LaMAl 11 O 19-δ samples, LaNiAl 11 O 19-δ showed the best catalytic activity for the reaction at 1 053 K for 2 h, the conversion of CH 4 and CO 2 was 98.8% and 97.6%, respectively, and the catalytic activities of rest Msubstituted catalysts were extremely lower than that of LaNiAl 11 O 19-δ . The sequence of affection on catalytic activity of transition metal M for the topic reaction was NiCo>Fe> Mn> Cu.展开更多
本文通过晶格取代作用 ,制备了以 Ni为活性组分的六铝酸盐复合氧化物催化剂 Sr Ni Al11O19-δ,并通过XRD,XPS,TPR等实验技术 ,对催化剂的结构和性质进行了表征。结果表明 ,六铝酸盐 Sr Ni Al11O19-δ对二氧化碳重整甲烷制合成气反应具...本文通过晶格取代作用 ,制备了以 Ni为活性组分的六铝酸盐复合氧化物催化剂 Sr Ni Al11O19-δ,并通过XRD,XPS,TPR等实验技术 ,对催化剂的结构和性质进行了表征。结果表明 ,六铝酸盐 Sr Ni Al11O19-δ对二氧化碳重整甲烷制合成气反应具有良好的催化活性和稳定性 ,在 780℃反应 2小时 ,CH4 和 CO2 转化率分别为 95 .0 %和 93 .4% ,没有发现活性组分 Ni高温烧结和催化剂失活。展开更多
A series of Ni modified hexaaluminates LaNi y Al 12- y O 19- δ ( y =0 3, 0 6, 0 9, 1 0) were prepared by decomposition of nitrates and calcination at high temperature. The crystalline structure and catalytic properti...A series of Ni modified hexaaluminates LaNi y Al 12- y O 19- δ ( y =0 3, 0 6, 0 9, 1 0) were prepared by decomposition of nitrates and calcination at high temperature. The crystalline structure and catalytic properties for CO 2 reforming of methane to synthesis gas were investigated by using XRD, XPS, TPR and TGA techniques. The results showed that a pure hexaaluminate LaNi y Al 12- y O 19- δ phase is formed only when y value is in 0< y ≤1. The reduced hexaaluminates LaNi y Al 12- y O 19- δ exhibit significant catalytic activity and stability for the reaction of CO 2 reforming of methane to synthesis gas at 780 ℃, and no deactivation resulting from carbon deposition is found. In the meantime, the catalytic activity is obviously affected by the modifier Ni in the hexaaluminate lattices. Under the same reaction conditions, the conversion of CH 4 and CO 2 increase with increase in the amount ( y value) of the modifier Ni.展开更多
文摘In this paper, the properties of carbon deposited on hexaaluminateLaNiAl_(11)O_(19) catalyst were characterized by X-ray photoelectron spectroscopy (XPS), and in themeantime, the amount of carbon deposited on the catalyst, after both CH_4 decomposition and CO_2reforming of CH_4, was determined by means of thermogravimetric analysis (TGA), respectively. Therates of carbon deposited on the catalyst were also investigated and the apparent kinetic equationof CO_2 reforming of CH_4: ν_c = kp^(0.72)(CH_4)·p^(-0.55)(CO_2), was established by analyzing therelation between the rates of deposited carbon and the pressure ratio of CH_4 and CO_2.
文摘A new type of the catalyst, LaNiAl11O19 for the methane reforming with carbondioxide was synthesized and evaluated. LaNiAl11O19 has a hexaaluminate structure and cankeep large surface and heat resistance against sintering at high reaction temperature. Ascompared with La2O3-Ni/SrAl12O19, in the CH4+CO2 reaction, LaNiAl11O19 catalyst displaysa higher catalytic activity, lower coking amount and excellent sintering resistance of Niparticle, due to its stable structure.
文摘In this paper, a series of hexaaluminate oxides, LaMAl 11 O 19-δ (M=Fe, Co, Ni, Mn and Cu), were prepared using transition metals M to substitute Al in the hexaaluminate lattices. XRD analyses indicated that the series of hexaaluminates had almost the same magnetoplumbite crystal structure, however, they exhibted different reducibility and catalytic activities for CO 2 reforming of methane to synthesis gas. Among the LaMAl 11 O 19-δ samples, LaNiAl 11 O 19-δ showed the best catalytic activity for the reaction at 1 053 K for 2 h, the conversion of CH 4 and CO 2 was 98.8% and 97.6%, respectively, and the catalytic activities of rest Msubstituted catalysts were extremely lower than that of LaNiAl 11 O 19-δ . The sequence of affection on catalytic activity of transition metal M for the topic reaction was NiCo>Fe> Mn> Cu.
文摘本文通过晶格取代作用 ,制备了以 Ni为活性组分的六铝酸盐复合氧化物催化剂 Sr Ni Al11O19-δ,并通过XRD,XPS,TPR等实验技术 ,对催化剂的结构和性质进行了表征。结果表明 ,六铝酸盐 Sr Ni Al11O19-δ对二氧化碳重整甲烷制合成气反应具有良好的催化活性和稳定性 ,在 780℃反应 2小时 ,CH4 和 CO2 转化率分别为 95 .0 %和 93 .4% ,没有发现活性组分 Ni高温烧结和催化剂失活。
文摘A series of Ni modified hexaaluminates LaNi y Al 12- y O 19- δ ( y =0 3, 0 6, 0 9, 1 0) were prepared by decomposition of nitrates and calcination at high temperature. The crystalline structure and catalytic properties for CO 2 reforming of methane to synthesis gas were investigated by using XRD, XPS, TPR and TGA techniques. The results showed that a pure hexaaluminate LaNi y Al 12- y O 19- δ phase is formed only when y value is in 0< y ≤1. The reduced hexaaluminates LaNi y Al 12- y O 19- δ exhibit significant catalytic activity and stability for the reaction of CO 2 reforming of methane to synthesis gas at 780 ℃, and no deactivation resulting from carbon deposition is found. In the meantime, the catalytic activity is obviously affected by the modifier Ni in the hexaaluminate lattices. Under the same reaction conditions, the conversion of CH 4 and CO 2 increase with increase in the amount ( y value) of the modifier Ni.
