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-Al₂O₃ (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-Al₂O₃. 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.

中文翻译：

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Co / Mo比对二苯并噻吩加氢脱硫中MgO纳米片负载的CoMo催化剂的形貌和活性的影响

MgO纳米片用于通过水共浸渍法制备具有不同Co / Mo比（CoMo / NA-MgO）的CoMo催化剂。随着CoMo催化剂中Co / Mo比的增加，CoMo / NA-MgO表现出对二苯并噻吩加氢脱硫的催化活性的提高，在Co / Mo比为0.5时达到最大活性。CoMo / NA-MgO-0.5的反应速率常数（k）和周转频率（分别为2.7×10 ^–7 mol g ^–1 s ^–1和7.9×10 ^–4 s ^–1）均高于常规CoMo。 /γ-Al系₂ ö ₃（2.1×10 ^-7摩尔克^-1小号^-1和4.1×10 ^–5 s ^–1）。鉴定结果显示，在NA-MgO的更基本的网站加强的MoO之间的相互作用_X和NA-氧化镁，导致的CoMo / NA-氧化镁具有更好的MoO _X比的CoMo /γ-Al系的分散₂ Ø ₃。此外，Co / Mo对CoMo / NA-MgO的增加削弱了MoO _x与NA-MgO的相互作用，导致更多的MoO _x物种在硫化后转变为堆叠度较低的II型CoMoS相，从而提高了直接脱硫活性。