β-Mo_2N_(0.78)/γ-Al_2O_3催化剂的制备及其噻吩加氢脱硫活性的研究

STUDIES ON SYNTHESIS OF β-Mo_2N_(0.78)/γ-Al_2O_3 CATALYST AND ITS CATALYTIC BEHAVIOUR FOR THIOPHENE HYDRODESULFURIZATION(HDS)

以γ Al2O3为载体,钼酸铵为氧化钼前驱体,采用在N2 H2气氛下的程序升温还原氮化反应,制备β Mo2N0 78/γ Al2O3催化剂,以噻吩为模型化合物,考察了该催化剂的加氢脱硫反应性能,以及反应温度、氢还原预处理和钴、镍助剂的引入等因素对催化剂活性的影响。结果表明,在320℃～400℃之间,随着反应温度的升高,催化剂的活性逐渐增加;预还原则降低了催化剂的活性;添加钴、镍均在一定负载量范围内可以改善β Mo2N0 78/γ Al2O3催化剂的加氢脱硫活性,但镍对催化剂活性的影响要小于钴。

Alumina supported β-Mo_2N_(0.78) catalysts were synthesized via temperature-programmed nitriding reaction of MoO_3 using N_2-H_2 mixture gas. The precursor of active phases was prepared by impregnation of γ-Alumina with aqueous solution of ammonium heptamolybdate((NH_4)_6Mo_7O_(24)·4H_2O), followed by drying and calcination in air. The hydrodesulfurization(HDS) reaction of thiophene over these catalysts was performed in a fixed-bed reactor at atmosphere pressure. The influence of HDS reaction temperature, pre-reduction of H_2 and the addition of Co and Ni on the activity of β-Mo_2N_(0.78)/γ-Al_2O_3 were studied. The results show that the HDS activity increases with increasing reaction temperature from 320℃ to 400℃. Pre-reduction can deactivate the activity of catalyst. The addition of Co and Ni can improve the catalytic activity of β-Mo_2N_(0.78)/γ-Al_2O_3 catalyst.