Khan Nazmul Abedin, Jhung Sung Hwa
Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University , Daegu 702-701, Republic of Korea.
Inorg Chem. 2015 Dec 7;54(23):11498-504. doi: 10.1021/acs.inorgchem.5b02118. Epub 2015 Nov 17.
Scandium-triflate (Sc(OTf)3) was introduced for the first time on metal-organic frameworks (MOFs), to utilize acidic Sc(OTf)3 for adsorptive desulfurization and denitrogenation of fuel containing benzothiophene (BT), dibenzothiophene (DBT), quinoline (QUI), and indole (IND). A remarkable improvement in the adsorption capacity (about 65% based on the weight of adsorbents; 90% based on the surface area of the adsorbents) was observed with the Sc(OTf)3/MOFs as compared to the virgin MOFs for the adsorption of BT from liquid fuel. The basic QUI was also adsorbed preferentially onto the acidic Sc(OTf)3/MOFs. However, nonsupported Sc(OTf)3 showed negligible adsorption capacities. The improved adsorptive performance for BT, DBT, and QUI might be derived from acid-base interactions between the acidic Sc(OTf)3 and basic adsorbates. On the other hand, the Sc(OTf)3, loaded on MOFs, reduced the adsorption capacity for neutral IND due to lack of interaction between the neutral adsorbate and acidic adsorbent and the reduced porosities of the modified adsorbents. The reusability of the adsorbents was found satisfactory up to the fourth run. On the basis of the result, it is suggested that metal-triflates, such as Sc(OTf)3, can be prospective materials for adsorptive desulfurization/denitrogenation of fuels when supported on porous materials such as MOFs.
三氟甲磺酸钪（Sc(OTf)₃）首次被引入金属有机框架材料（MOFs）中，以利用酸性的Sc(OTf)₃对含苯并噻吩（BT）、二苯并噻吩（DBT）、喹啉（QUI）和吲哚（IND）的燃料进行吸附脱硫和脱氮。与原始MOFs相比，Sc(OTf)₃/MOFs对液体燃料中BT的吸附能力有显著提高（基于吸附剂重量约为65%；基于吸附剂表面积为90%）。碱性的QUI也优先吸附在酸性的Sc(OTf)₃/MOFs上。然而，未负载的Sc(OTf)₃吸附能力可忽略不计。对BT、DBT和QUI吸附性能的改善可能源于酸性Sc(OTf)₃与碱性吸附质之间的酸碱相互作用。另一方面，负载在MOFs上的Sc(OTf)₃降低了对中性IND的吸附能力，这是由于中性吸附质与酸性吸附剂之间缺乏相互作用以及改性吸附剂孔隙率降低所致。吸附剂的可重复使用性在第四次循环之前表现令人满意。基于该结果，表明当负载在MOFs等多孔材料上时，金属三氟甲磺酸盐，如Sc(OTf)₃，有望成为燃料吸附脱硫/脱氮的材料。
