Akopyan Argam V, Polikarpova Polina D, Arzyaeva Nina V, Anisimov Alexander V, Maslova Olga V, Senko Olga V, Efremenko Elena N
Faculty of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow 119991, Russia.
Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygina st., 4, Moscow 119334, Russia.
ACS Omega. 2021 Oct 7;6(41):26932-26941. doi: 10.1021/acsomega.1c03267. eCollection 2021 Oct 19.
We have studied for the first time the role of hydrophobicity of the mesoporous silicate SBA-15 on the activity and the service life of a catalyst in the peroxide oxidation of sulfur-containing compounds. Immobilization of the molybdate anion on the SBA-15 support via ionic bonding with triethylammonium groups allows us not only to decrease the reaction temperature to a relatively low value of 60 °C without a drop in the dibenzothiophene conversion degree but also to increase the service life of the catalyst to many times that of the known analogs. The support and catalyst structures were investigated by low-temperature nitrogen adsorption/desorption, Fourier-transform infrared spectroscopy, X-ray fluorescence analysis, and transmission electron microscopy. Immobilization of the molybdate anion on the SBA-15 support, modified with ammonium species, prevents the leaching of active sites. However, only alkyl-substituted ammonium species minimize DBT sulfone adsorption, which significantly increases the catalyst's service life. The synthesized catalyst Mo/EtN-SBA-15 with hydrophobic properties is not sensitive to the initial sulfur content and hydrogen peroxide amount and retains its activity for at least six cycles of oxidation without regeneration. These catalysts can be efficiently used for clean fuel production.
我们首次研究了介孔硅酸盐SBA - 15的疏水性对含硫化合物过氧化反应中催化剂活性和使用寿命的影响。通过与三乙铵基团的离子键合将钼酸根阴离子固定在SBA - 15载体上，不仅能将反应温度降低至相对较低的60°C，而二苯并噻吩转化率却不下降，还能将催化剂的使用寿命提高至已知类似物的数倍。通过低温氮吸附/脱附、傅里叶变换红外光谱、X射线荧光分析和透射电子显微镜对载体和催化剂结构进行了研究。将钼酸根阴离子固定在经铵物种改性的SBA - 15载体上可防止活性位点的浸出。然而，只有烷基取代的铵物种能使二苯并噻吩砜吸附最小化，这显著提高了催化剂的使用寿命。合成的具有疏水性质的催化剂Mo/EtN - SBA - 15对初始硫含量和过氧化氢量不敏感，并且在无需再生的情况下至少能保持六个氧化循环的活性。这些催化剂可有效地用于清洁燃料生产。
