Photocatalytic degradation of methylene blue with spent FCC catalyst loaded with ferric oxide and titanium dioxide

Jiasheng Xu,Te Zhang,Jie Zhang

doi:10.1038/s41598-020-69643-2

Abstract

The spent fluid catalytic cracking (FCC) catalyst has been loaded with ferric oxide (Fe2O3) and titanium dioxide (TiO2). Fe-Ti/SF composite (loaded with 5 wt% TiO2 and 5 wt% Fe2O3), Fe/SF composite (loaded with10 wt% Fe2O3) and Ti/SF composite (loaded with 10 wt% TiO2) have been fabricated via a modified-impregnation method. The band gaps of the Fe-Ti/SF, Fe/SF and Ti/SF composites (evaluated by the energy versus [F(R∞)hv]n) are 2.23, 1.98 and 3.0 eV, respectively. Electrochemical impedance spectroscopy shows that the Fe-Ti/SF has lower electron transfer resistance, it has the small charge transfer resistance and fast charge transfer rate. The interparticle electrons transfer between the Fe2O3 and TiO2, which can improve the separation of the photo-electrons and holes. The holes transfer from valence band of TiO2 to the valence band of Fe2O3, which can provide more active sites around the adsorbed molecules. The methylene blue degradation efficiencies (with the Fe-Ti/SF, Fe/SF and Ti/SF composites) are ~ 94.2%, ~ 22.3% and ~ 54.0% in 120 min, respectively. This work reveals that the spent FCC catalyst as supporter can be loaded with Fe2O3 and TiO2. This composite is highly suitable for degradation of methylene blue, which can provide a potential method to dispose the spent FCC catalyst in industry.

Highlights

In the oil refinery, the fluid catalytic cracking (FCC) is an important secondary conversion p rocrss[1,2,3,4]
In a typical experimental procedure, the spent FCC catalyst was loaded with titanium dioxide (5 wt% TiO2) and ferric oxide (5 wt% Fe2O3), it was prepared as follows. 0.85 mL tetrabutyl titanate and 0.31 g ammonium ferric oxalate were dissolved into 4 mL of H2O2 solution (~ 30%)
4 g spent FCC catalyst was added into this solution

Summary

Introduction

The fluid catalytic cracking (FCC) is an important secondary conversion p rocrss[1,2,3,4]. The charge carrier of the T iO2 is fast recombinated, which can be prevented effectively by the heterogeneous structures (with the narrow band gap semiconductor materials). Spent FCC catalyst loaded with Fe2O3 and TiO2 was fabricated via a modified-impregnation method. This work is that it provides a new way to treat spent FCC catalyst. The spent FCC catalyst are mainly treated by landfill. This method caused severe land pollution and polluted groundwater. The novelty of this work is the introduction spent FCC catalyst as supporter. These composites fabricated via this modified-impregnation method can provide an effective route to dispose the spent FCC catalyst in industry

Methods

Results

Conclusion