载体表面修饰对Cu-Co-Fe/Al_2O_3合成醇催化剂性质的影响

Effect of Surface Modification of Support on Properties of Cu-Co-Fe/Al_2O_3 Catalyst for Alcohol Synthesis

采用不同 pH值的HNO3 或KOH水溶液对Al2 O3 载体表面进行修饰 ,研究了修饰后Cu Co Fe1.2 /Al2 O3 合成醇催化剂的物相结构、表面性质和还原行为的变化规律 .发现载体的表面修饰不仅能影响活性组分的物相结构和分散度 ,而且能改变活性组分与载体间的相互作用程度和催化剂的孔径分布 .在低pH值溶液中修饰的载体上 ,Co组分容易分散 ,而在高 pH值溶液中修饰的载体上 ,Cu组分容易分散 .随着修饰液pH值的增大 ,Cu Co Fe1.2 /Al2 O3催化剂的还原温度先降低 ,经过最低点后升高 。

The Cu-Co-Fe-1.2/Al2O3 alcohol synthesis catalyst was prepared from the alumina support modified with HNO3 or KOH aqueous solution at different pH. The effects of modification conditions on the phase, surface and reduction behavior of the catalyst were studied. With increasing pH value, the dispersion of CuO on the support becomes easier and the mean pore size of the catalyst decreases. The Co component is well dispersed on the support modified at low pH. The reduction temperature of the catalyst decreases at first, and then increases when the Al2O3 support is modified at pH of 6 to 13.