Recyclable Cu(i)/ZrSBA-15 prepared via a mild vapor-reduction method for efficient thiophene removal from modeled oil

Abstract

Nowadays, processing of ultra-low sulfur fuel oil has been a hot topic of research all over the world; hence, an efficient adsorption process to tackle this issue is eliciting increasing attention. However, the preparation of high-performance adsorbents is still a challenge. Herein, zirconium-substituted mesoporous SBA-15 with highly dispersed active Cu(I) species has been successfully synthesized by our group at 493 K via a mild vapor-reduction method. The as-prepared material was characterized by powder X-ray diffraction (XRD), nitrogen adsorption and desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis diffuse reflectance (DRUV) spectroscopy. All characterization methods demonstrated that the Cu(I) species were highly dispersed in an ordered mesoporous framework with short channels rather than piled on the surface. The as-prepared materials also exhibited an excellent adsorption capacity for thiophene (up to 29.86 mg g⁻¹ at 323 K). Pseudo-second-order kinetics model and Freundlich isotherm can well describe the adsorption kinetics and isotherm data, respectively. More remarkably, an ultrasound-assisted treatment can be effectively employed to regenerate adsorbent, with only a slight reduction in the adsorption capacity after five cycles.