Ni/MgO/Al_2O_3催化剂中Ni前体对甲烷-二氧化碳重整反应活性的影响

Effect of Nickel Precursor on the Catalytic Activity in Carbon Dioxide Reforming of Methane on Ni/MgO/Al_2O_3 Catalysts

考察了以硝酸镍、氯化镍、硫酸镍、醋酸镍及硝酸六氨合镍 5种 Ni盐制备的 Ni/Mg O/Al2 O3 催化剂在CO2 与 CH4重整制合成气反应中的催化活性 .发现 Ni前体对活性有明显的影响 .以硝酸镍、醋酸镍、硝酸六氨合镍为前体制备的 Ni催化剂 ,反应活性较高 ;以硫酸镍为前体制备的 Ni催化剂 ,可能由于硫中毒等原因而显示出很低的活性 ;以氯化镍为前体制备的 Ni催化剂 ,其活性与制备方法有关 ,未经焙烧而直接还原的催化剂显示出较好的活性 .X-射线粉末衍射 (XRD)、BET比表面积及反应后的积炭量测定结果表明 ,以硝酸镍、醋酸镍、硝酸六氨合镍为前体制备的 Ni催化剂 ,表面分散性好 ,比表面积大 。

s: The catalytic activities of Ni/MgO/Al\-2O\-3 catalysts prepared using different nickel compounds as the precursors were studied for the carbon dioxide reforming of methane. It is found that the properties of nickel precursors employed play an important role in the catalyst preparation. The nickel catalysts based on hexaamminenickel nitride, nickel nitrate and nickel acetate exhibit good activity because of better dispersion of nickel on the catalyst surface. In contrast, the catalyst prepared using nickel sulfate shows almost no activity, which is probably due to the sulfur poisoning. The activity of the catalyst derived from nickel chloride depends on the preparation method. The catalyst prepared by impregnation\|calcination\|\{reduction\} method is found to have lower activity than that of the catalyst prepared by impregnation\|reduction method.