金属分散度对Ni基催化剂催化活性的影响研究

Study on the Effect of Metal Dispersion on the Catalytic Activity of Nickel⁃Based Catalysts

鞠雅娜 张雅琳 张然 宋绍彤 吕忠武 袁晓亮 李阳 吴培

Yana Ju Yalin Zhang Ran Zhang Shaotong Song Lü Zhongwu Xiaoliang Yuan Yang Li Pei Wu

中国石油天然气股份有限公司 石油化工研究院，北京 102206

PetroChina Petrochemical Research Institute，Beijing 102206，China

以γ?Al2O3为载体、Ni为活性组元，通过引入助剂Mo改善Ni系催化剂金属分散度，制得NiMo/γ?Al2O3催化剂（NiMo系催化剂）。采用BET、XRD、H2?TPD、H2?TPR、透射电镜等多种表征手段对催化剂进行了物性表征，并利用加氢装置对催化剂性能进行评价，考察了金属分散度对催化剂催化活性的影响。结果表明，Mo的引入可有效减弱Ni与载体的相互作用，H2?TPR谱图低温还原峰明显前移，峰强度增强，催化剂活性比表面积由0.7 m2/g增加到15.3~16.1m2/g，金属分散度由0.80%提高到18.59%，增加了催化剂表面金属活性中心数量，提高了催化剂表面金属分散度；在相同的工艺条件下处理催化裂化重汽油，NiMo系催化剂较Ni系催化剂脱硫率提高了15.7%，烯烃饱和率提高了4.9%，脱硫选择性降低了3.4%。由此可见，NiMo系催化剂兼具较好的脱硫性能和脱硫选择性。

NiMo/γ?Al2O3 catalyst was prepared by using γ?Al2O3 as the carrier and Ni as the active component,and Mo was introduced to improve the metal dispersion of Ni?based catalysts.The physical properties of the catalysts were characterized by means of BET,XRD,H2?TPD,H2?TPR,and transmission electron microscopy.The performance of the catalysts was evaluated by hydrogenation units,and the effect of metal dispersion of the catalysts on the catalytic activity was investigated.The results show that the introduction of Mo can effectively weaken the interaction between Ni and the carrier.The low?temperature reduction peak of the H2?TPR profile significantly moves forward,and the peak intensity is enhanced.The specific surface area of the catalyst activity increases from 0.7 m2/g to 15.3~16.1 m2/g,and the metal dispersion increases from 0.80% to 18.59%,which indicates that the number of metal active centers on catalyst surfaces increases,and the metal dispersion on the catalyst surfaces improves. Under the same process condition,heavy petrol with catalytic cracking is processed,and the desulfurization rate of NiMo?based catalysts is increased by 15.7% compared with that of Ni?based catalysts.The saturation rate of olefin is increased by 4.9%,and the desulfurization selectivity is decreased by 3.4%.Therefore,the NiMo?based catalysts have positive desulfurization selectivity while ensuring a high desulfurization rate.

国家自然科学基金项目(ZX20200125)

10.3969/j.issn.1006-396X.2022.05.008