###### Abstract  
A mesoporous silica-supported molybdenum oxide catalyst with a cerium(Ce) modifier was prepared by in situ synthesis and used in a hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)) system for the desluffurization of dibenzothiophene (DBT), benzothiophene (BT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) fuel oils. The catalytic performance of the catalyst was studied. The catalyst was characterized by Fourier Transform Infra-Red (FT-IR), X-ray diffraction (XRD), Brunner\(-\)Emmet\(-\)Teller (BET), and X-ray Photoelectron Spectroscopy (XPS). The influences of \(m\)(catalyst)/\(m\)(fuel oil), \(v\)(H\({}_{2}\)O\({}_{2}\))/\(v\)fuel oil), reaction temperature, and reaction time were investigated. The catalyst had excellent catalytic oxidation desluffurization performance under moderate operational conditions. The catalytic performance was in the order DBT > 4,6-DMDBT > BT. The kinetic analysis results showed that the reaction was a pseudo first-order kinetics process and the apparent activation energies of DBT, BT, and 4,6-DMDBT were 46.67 kJ/mol, 56.23 kJ/mol, and 55.54 kJ/mol, respectively. The reaction products of DBT, BT, and 4,6-DMDBT were DBTO\({}_{2}\), BTO\({}_{2}\), and 4,6-DMDBTO\({}_{2}\), respectively. The recycling experiments indicated that DBT, BT, and 4,6-DMDBT removal could still reach levels of 94.0%, 63.0%, and 77.9% after five cycles. mesoporous silica; molybdenum oxide; cerium; catalytic oxidation desluffurization; kinetics 40.0000  
selectivity in removing aromatic sulfur compounds in contrast with HDS, without the need for expensive hydrogen [11]. The oxidative desulfurization process is divided into two stages. First, the sulfur-containing compounds are oxidized to sulfones in the existence of an oxidizer [12]. Second, these sulfones in the mixture are gotten rid of through adsorption. In catalytic oxidation desulfurization, the oxidant is very important as an indispensable part of the process. The most commonly used oxidants are hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)), oil-soluble oxidants, gas oxidants, and solid oxidants [13]. Among them, H\({}_{2}\)O\({}_{2}\) is currently the most suitable oxidant for oxidative desulfurization [14]. It is cheap and non-corrosive, so it is harmless to the reaction equipment [15]. The catalyst also plays a vital role in the oxidation desulfurization procedure. At present, the most commonly used catalysts are organic acid catalysts, polyoxometalate catalysts, ionic liquids, transition metal oxide catalysts, and inorganic non-metallic catalysts [16]. Among them, molybdenum oxide has received extensive attention. Due to the high valence of Mo and the small ion radius, molybdenum-based catalysts display perfect catalytic performance. [PERSON] [17] et al. reported that Molybdenum trioxide/aluminium oxide(MoO\({}_{3}\)/Al\({}_{2}\)O\({}_{3}\)) was used as a catalyst and H\({}_{2}\)O\({}_{2}\) was used as an oxidizer for catalytic oxidative desulfurization, which had good desulfurization performance. At the same time, the catalyst carrier also has a particular influence on the desulfurization performance. Among them, titanium dioxide, activated carbon, alumina, silica, etc., have received extensive attention [18]. Silica is widely used due to its easy production, low price, and rich surface pore structure [19]. [PERSON] [20] et al. reported the preparation of a mesoporous silica material containing phosphomolybic acid and investigated its oxidative desulfurization performance. We could ascertain that the removal effect of sulfur compounds was superior. Studies have shown that adding a certain amount of modifier to the catalyst can improve the catalytic performance and selectivity. Transition metal and lanthanides are the most commonly used modifiers. [PERSON] [21] et al. reported that La\({}^{3+}\) was used as a modifier to prepare a phosphomolybic acid-supported Silicon dioxide(SiO\({}_{2}\)) catalyst. The results illustrated that the catalytic performance was further improved after the modifier was added in comparison to before.