Hierarchical porous HKUST-1 fabricated by microwave-assisted synthesis with CTAB for enhanced adsorptive removal of benzothiophene from fuel

Ultra-deep removal of thiophene sulfides from transportation fuel via adsorption has aroused great attention under the pressure of gradually demanding environmental regulations. The development of high-efficiency adsorbents is the key to adsorptive desulfurization for producing clean transportation fuels. In this work, a microwave-assisted synthesis method was applied to rapidly fabricate hierarchical porous defective HKUST-1 (DEHKUST-1) towards removing benzothiophene from model fuel by selective adsorption. The effects of cetyltrimethylammonium bromide (CTAB) dosage, adsorption temperature and adsorption contact time on the DEHKUST-1 desulfurization performance were systematically investigated. The characterization results proved that both metal clusters and linker defects were generated in the as-prepared DEHKUST-1. CTAB as template could modulate the pore distribution and introduce reasonable defects in the framework of HKUST-1. At CTAB: Cu2+ = 0.5 by mole ratio, a regular mesoporous distribution of 25-30 nm could be obtained with DEHKUST-1; it exhibited an impressive enhancement in adsorptive desulphurization performance. The maximum adsorption capacity of the adsorbent attained 14.4 mg S/g adsorbent at 20 degrees C in 4 h. Even after CTAB-H-0.5 was regenerated six times, its adsorption capacity remained 93% as that of the as-prepared adsorbent. An adsorption mechanism was proposed to illustrate the promoting desulfurization performance by introduction of hierarchical porous in HKUST-1. By virtue of the rapid synthesis and remarkable benzothiophene removal capacity, the DEHKUST-1 could be a potential adsorbent in desulfurization from real fuels.