稀土在负载型非晶态NiB/Al_2O_3合金上作用研究

Effect of Rare Earth on Supported Amorphous NiB/Al_2O_3 Catalyst

本文采用脉冲技术研究了稀土氧化物对负载型非晶态 Ni B/Al2 O3合金催化剂苯加氢活性和抗硫性能的影响。用 XRD鉴定了非晶态结构 ,用 TPR、TPD表征了催化剂的表面性质 ,用 CO化学吸附法测定了活性镍表面积。实验结果表明 ,非晶态合金催化剂上至少有两种吸附中心 ,稀土氧化物能明显地提高催化剂的苯加氢活性和抗硫性能 ,其原因是稀土氧化物有助于氧化镍的还原 ,从而在反应温度下有更多的活性镍物种被还原 ,稀土氧化物还能使镍物种颗粒细化 ,提高了活性镍面积。

The technique of pulse microreaction was applied to study the effect of RE on catalytic activity and sulfur resistance of supported amorphous NiB/Al 2O 3 catalyst for benzene hydrogenation.The amorphous structure was analyzed by XRD;the surface properties of the alloys were characterized by TPR and TPD;the surface areas of active nickel were measured by CO chemical absorption.Results showed that there existed two absorption at least.The addition of RE obviously improved the catalytic activity and sulfur resistance.The reason is that RE was helpful to the reduce of nickel oxide and made more nickel species reduced at reaction temperature.RE also could make the nickel particles smaller and improve the surface areas of active nickel.