载体的酸性和钠含量对Ni-Mo催化剂加氢脱硫性能的影响

THE EFFECT OF ACIDITY AND SODIUM CONTENT OF SUPPORT ON THE HDS PERFORMACE OF Ni-Mo CATALYSTS

用MCM-41和Na交换的MCM-41(NaMCM-41)以及它们与NaY和HY沸石的机械混合物为载体负载Ni-Mo制备了加氢脱硫(HDS)催化剂,用ICP-AES、吡啶吸附红外、UV-Vis、TPR等对载体和所制备的催化剂进行了表征。以二苯并噻吩(DBT)为模型化合物评价了催化剂的HDS活性,考察了载体的酸性和Na含量对催化剂HDS活性的影响。发现Ni-Mo催化剂的HDS活性与载体的Na^+含量和B酸量有关,而与L酸量关系不大。通过催化剂的HDS反应和TPR表征结果,发现在载体酸中心和活性组分之间可能存在着以溢流氢为纽带的协同作用。

A series of Ni-Mo HDS catalysts were prepared by using various supports including MCM-41, NaMCM-41, HY, NaY and their mechanical mixtures. The supports and the catalysts were characterized by TPR, UV-Vis, ICP-AES and IR. The HDS activities of these prepared catalysts were evaluated using dibenzothiophene （DBT） as model compound to study the effect of support acidity and sodium content on the HDS activity of catalyst. It is found that the HDS activities of these catalysts are related to the Bronsted acidity and sodium contents of the supports： Bronsted acidity has a positive effect on the HDS activity of the supported Ni-Mo catalysts while Na^＋ has a negative effect. Furthermore, it seems that some synergetic effects exist between the acid sites of support and the active components linking by spillover hydrogen as shown from the results of TPR characterization and HDS evaluation.