负载型氮化钴钼催化剂的制备及催化性能

Synthesis Conditions and Catalytic Activity of the Supported CoMo Nitride Catalysts

严格的环境法规规定了燃料中硫的质量分数,要求对燃料中的含硫成分进行深度脱硫,开发新型高效催化剂是降低硫的质量分数的一个有效方法。过渡金属氮化物是一种新型催化材料,其表面性质和催化性能类似于贵金属。通过一步浸渍法和分步浸渍法合成出氧化态催化剂,并以氢气和氮气通过程序升温还原反应制备出负载型氮化钴钼双金属催化剂,用模型化合物噻吩对催化剂的加氢脱硫性能进行了考察。结果表明,用分步浸渍法合成出的BⅡ类氮化钴钼催化剂的噻吩加氢脱硫活性最高;在其它条件相同情况下,高温、预活化有利于噻吩加氢脱硫反应,合成的AⅡ、BⅡ类催化剂HDS催化性能与氮化后的工业催化剂接近。应用氮化态催化剂可以避免因工业催化剂预硫化而带来的硫污染,因此具有广泛的应用前景。

Strict environmental regulation on the amounts of sulfur in fuel can be expected to be the driving force for deeper HDS to desulfurize the more stable sulfur-containing molecules, and developing new type of catalysts possessing high activities is an effective method to eliminate undesirable sulfur. Transition metals nitrides which properties of surface and catalysis activities analogies with noble metals,is an advanced catalytic material. Supported oxide bimetalic catalysts have been obtained through impregnant and step impregnant methods. Using the temperture-programed reaction with mixture gas of N2 and H2 produced supported CoMo nitride catalyst. Hydrodesulfurization activity of removing thiophene on the catalysts had been studied. The results show that the activity of hydrodesulfurization on BⅡ nitride catalysts is the better. With the increasing of temperature and prereduced catalyst, the activity of hydrodesulfurization is progressed. The AⅡ?BⅡ nitride catalysts have the similar activity for hydrodesulfurization with nitrided industry catalyst. Nitride catalysts have considerable potential application because prereduction avoided the sulfuric pollution caused by presulfurization.