Defect engineering and post-synthetic reduction of Cu based metal–organic frameworks towards efficient adsorption desulfurization

• ADS performance of the best CuBDC-x is 104.5% higher than the original CuBDC. • Both the defects and porosity can be regulated by a defect engineering method. • A convenient ethanol thermal treatment is developed to reduce Cu 2+ to Cu + . • Cu + rather than Cu 2+ are demonstrated to be the adsorption site of mercaptan. Adsorption desulfurization (ADS) is one of the most potential technologies for desulfurization of gasoline, while developing adsorbents with high sulfur capture capability to meet the strict environmental regulations remains a challenge. Here, a series of CuBDC-x adsorbents containing additional defects and enhanced adsorption sites via modulator-induced defect engineering and subsequent post-synthetic reduction strategy were synthesized. The optimal CuBDC-1 samples showed a remarkable sulfur adsorption capacity of 41.1 mg S/g in model fuel, which is 104.5% higher than that of original CuBDC. The Cu + rather than Cu 2+ cations in MOFs were found to be the main adsorption sites for mercaptan molecules. This work offers a new insight into developing high-efficiency adsorbent for ultra-deep desulfurization.