BET and XPS measurements revealed that the change of pore distribution, the partial loss of Ni and Ce species over the surface of Ni-Ce/Al 2O 3 after using for a long time in this reaction system are responsible for the decrease of the catalyst activity.

• BET ,XPS表征显示 ,经过较长时间反应的Ni Ce/Al2 O3 催化剂 ,其孔径分布的变化以及活性物种Ni和助剂Ce向体相的迁移或流失 ,有可能是造成该类催化剂活性逐步下降的主要原因