研究了以冷轧工艺制备的Ni3Al单晶箔(Ni-24at%Al),以及表面预处理(873K下蒸汽氧化后还原处理)后的Ni3Al箔,在甲烷重整制氢反应中的催化性能.首先,采用逐步升温法研究了873～1173 K下Ni3Al箔的催化活性与温度的关系;然后,采用等温法研究了973 K下Ni3Al箔的催化稳定性.根据催化反应和扫描电镜显微观察的结果得出:未经预处理和经过预处理的Ni3Al箔,在反应中均显示出一定的催化活性和稳定性;表面预处理对Ni3Al箔的催化活性有显著的增强作用,原因是经过该预处理后的Ni3Al箔形成了富Ni表面;Ni3Al箔在甲烷重整反应的气氛中,Ni原子从Ni3Al基体向表面的移动,是维持催化活性的主要原因.%The catalytic activity of Ni3Al foils for methane steam reforming was investigated by isochronal test from 873 to 1173 K, and the stability at 973 K for 20 h was also studied by isothermal test.Further, the effect of pretreatment, which was steam-oxidation then reduction at 873 K on the catalytic property, was also investigated.The results of catalytic reactions and the microstructure observations by SEM showed that the Ni3Al foils whether or not through the pretreatment all had certain activities and stabilities.The pretreatment significantly enhanced the catalytic activity of Ni3Al foils.Ni-enriched outer surface formed after the pretreatment was thought as the main reason of the enhancement.It was also considered that the Ni atoms moved from the matrix of Ni3Al foils to the outer surface during the reactions were attributed to the catalytic stabilities.
展开▼
