含钴WP/MCM-41催化剂二苯并噻吩加氢脱硫性能

Dibenzothiophene Hydrodesulfurization Performance of WP/MCM-41 Catalysts Containing Cobalt

制备了不同Co含量的WP/MCM-41催化剂,并采用X-射线衍射(XRD)、BET比表面积以及X-光电子能谱(XPS)等分析手段对催化剂进行了表征,采用微反装置对该催化剂二苯并噻吩(DBT)加氢脱硫(HDS)性能进行了评价。结果表明,WP是催化剂的主要活性相,Co的加入不同程度地促进了WP晶相生长,同时在催化剂表面形成了具有一定活性的类似Co—W—P结构的双金属磷化物。Co对WP/MCM-41催化剂的DBT HDS反应有促进作用,催化剂中活性位数量以及主要活性相WP在催化剂表面所占比例是决定催化剂活性的主要因素。其中,Co质量分数为9%的催化剂(Cat-Co-9)具有相对最高DBT HDS活性,其DBT脱硫率和转化率分别为63.7%和60.4%,比未加Co的催化剂分别提高13.2%和13.7%。DBT在WP/MCM-41催化剂上以加氢脱硫(HYD)路径为主,Co的加入对HYD路径起到促进作用,但随着Co加入量的提高,其HYD路径产物选择性逐渐降低,而直接脱硫(DDS)路径产物选择性不断提高。

WP/MCM-41 catalysts containing different Co contents were prepared,and characterized by X-ray diffraction（XRD）,BET and X-ray photoelectron spectroscopy（XPS）.The catalytic performance of the catalysts for dibenzothiophene（DBT） hydrodesulfurization（HDS） was evaluated in a fixed-bed microreactor.The results showed that the addition of Co was favor to improve the growth of active species WP to some extent,which was the main active phase,and the bimetallic phosphide with a similar structure of Co—W—P was probably formed in the surface of catalyst when Co was added.The Co had a positive effect on the catalytic activity of WP/MCM-41 catalysts for DBT HDS.The catalytic activity of WP/MCM-41 depended on the number of active site and the proportion of main active phase WP on the catalyst surface.The catalyst containing Co mass fraction of 9% displayed the highest HDS activity among these Co containing WP/MCM-41,with the DBT desulfurization rate and conversion rate of 63.7% and 60.4%,respectively,13.2% and 13.7% higher than that without Co.The hydrogenation（HYD） route was the dominant path for the WP/MCM-41 catalysts containing different Co contents in DBT HDS reaction,while the of HYD route selectivity was decreased and the direct desulfurization（DDS） route selectivity was increased with the Co content increasing.