Effect of the Co/Mo Ratio on the Morphology and Activity of the CoMo Catalyst Supported on MgO Nanosheets in Dibenzothiophene Hydrodesulfurization

Abstract

MgO nanosheets were employed to prepare CoMo catalysts with different Co/Mo ratios (CoMo/NA-MgO) by an aqueous co-impregnation method. CoMo/NA-MgO displayed an increase in the catalytic activity for hydrodesulfurization of dibenzothiophene as the Co/Mo ratio increased in the CoMo catalysts, and it reached maximal activity at the Co/Mo ratio of 0.5. The reaction rate constant (k) and turnover frequency of CoMo/ NA-MgO-0.5 (2.7 × 10 −7 mol g −1 s −1 and 7.9 × 10 −4 s −1 , respectively) were higher than those of conventional CoMo/γ-Al 2 O 3 (2.1 × 10 −7 mol g −1 s −1 and 4.1 × 10 −5 s −1 ). Characterization results revealed that more basic sites on NA-MgO strengthen the interaction between MoO x and NA-MgO, leading to CoMo/NA-MgO with better MoO x dispersion than that of CoMo/γ-Al 2 O 3 . In addition, an increase in Co/Mo for CoMo/NA-MgO weakened the interaction of MoO x with NA-MgO, leading to more MoO x species transformed into a less stacked type II CoMoS phase after sulfidation, improving direct desulfurization activity.

Hydrodesulfurization of Gas Condensate containing Di-Sulfide Oil: Catalyst synthesis and evaluation

“…It seems that an increase in Co/Mo ratio can enhance the active sites. Furthermore, the catalytic activity may be declined in the presence of CoMoS species in the molar ratios more than 0.55 .These results support the data reported in previous studies by Zhang et al [28]. Moreover, the catalyst showed a reduction in efficiency at Co/Mo ratios less than 0.35.…”

Study on Diesel Hydrotreating Kinetics and the Synergistic Effect of CoMo and NiMo Catalysts

“…Meanwhile, many scholars have also conducted extensive research on the commonly used CoMo catalyst for diesel hydrotreating reactions. Zhang et al conducted research on the ratio of Co to Mo during the preparation of CoMo catalysts, which enhanced the performance of the catalyst. Ghani et al , discussed the effect of inhibition on the joint reactions of hydrodenitrogenation and hydrodesulfurization.…”

Hydrodesulfurization of Thiophene in n-Heptane Stream Using CoMo/SBA-15 and CoMo/AlSBA-15 Mesoporous Catalysts

“…Active metal loading and unfavorable interactions have limited supported HDS catalysts to produce ultra-low sulfur fuels. Thus, several studies have been carried out aiming to improve the performance of HDS in relation to the following aspects: modification of zeolite supports, such as ZSM-5 [12][13][14] and Y zeolite [15], materials based on mesoporous silica, such as MCM-41, SBA-15, and SBA-16 [16][17][18][19], oxides single and mixed metallic [20][21][22][23][24][25][26], and carbon-based materials [27][28][29][30][31][32][33]. However, the development of new catalysts containing well-defined micro-and mesopores requires further research and additional modifications for evaluation as new supports for ultra-deep desulfurization.…”