摘要
以MCM-41为载体,以镍(Ni)为助剂,制备了Ni含量不同的WP/MCM-41催化剂。采用XRD、BET、SEM和XPS对催化剂进行了表征;以二苯并噻吩(DBT)为模型化合物,通过高压微反装置考察催化剂的加氢脱硫(HDS)活性。结果表明,Ni的加入促进了活性组分WP的生长并使其晶相尺寸略有增加,一定含量的Ni有利于提高催化剂的比表面积。Ni对WP/MCM-41催化剂二苯并噻吩HDS反应具有促进作用。少量Ni的加入有利于WP活性相的生成并增加了活性位的数量;加入过量的Ni,在催化剂中形成了具有一定活性的类似Ni-W-P结构的物种,减少了活性组分WP所占的比例,从而使催化剂DBT的HDS活性降低。其中,Ni的质量分数为1%的催化剂(cat-Ni-1)具有相对较高活性,其DBT脱硫率和转化率分别为76.78%和72.16%,比不加Ni的催化剂分别提高了30.04%和21.62%。二苯并噻吩在WP/MCM-41催化剂上以加氢脱硫途径为主,Ni的加入对提高加氢脱硫途径选择性起到了促进作用,且加氢脱硫选择性随Ni含量的增加而提高。
The supported tungsten phosphide catalysts with different content of nickle were prepared over MCM- 41. The samples were characterized by Xray diffraction（ XRD）, BET specific surface area, scanning electron microscopy （ SEM ） and Xray photoelectron spectroscopy （ XPS ） methods. The dibenzothiophene （ DBT ） hydrodesulfufizafion（HDS） performance of catalysts was evaluated in a fixde-bed reactor at 633 K, 3 MPa H2 and with a space velocity of 4 h-1. The results showed that the addition of Ni promoted the growth of active species WP and increased WP crystal dimension. Some content of nickel was favor to increase the BET specific surface area of catalyst. Ni had positive effects on the DBT HDS reaction of WP/MCM-41 catalysts. WP was the main active phase. The addition of small amount （ 1% ） of nickle was favor to the formation of WP active phase and increased the active site number. The addition of excess content （5%, 9% ） of nickel probably conduced the formation of a new active species with similar structure of Ni-W-P, which decreased the proportion of WP active phase on the catalyst surface and resulted in the decline of catalytic activity. Particularly, the catalyst with nickel content of 1% had high HDS activity, giving the DBT desulfurization rate and DBT conversion rate of 76.78% and 72. 16%, respectively, which were 30.04% and 21.62% higher than those given by the catalyst without nickel addition. The hydrodesulfufization （HYD） was the dominant path for WP/ MCM-41 catalysts in DBT HDS reaction. The HYD selectivity was improved with the increasing of nickel content of catalyst.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2011年第12期930-935,共6页
Journal of Fuel Chemistry and Technology
基金
北京市自然科学基金(2052009)
北京市属高校人才强教深化计划(PHR200907129)
北京市教委项目(ZR2008345)
关键词
加氢脱硫
二苯并噻吩
磷化钨
MCM-41
助剂
镍
hydrodesulfurization
dibenzothiophene
tungsten phosphide
MCM-41
promoter
nickle
