Preparation of metal-doped Cu–Mn/HTS-1 catalysts and their mechanisms in efficient degradation of toluene
Lei Yu
,
Jianrui Niu
,
Haobin Liu
,
Hengli Qian
,
Jie Liu
,
Mengyuan Ma
,
Erhong Duan
DOI:10.1016/j.jes.2019.08.019
Received May 06, 2019,Revised , Accepted August 30, 2019, Available online September 11, 2019
Volume 32,2020,Pages 260-272
In order to study their synergistic catalytic effects in toluene degradation, CuMn2O4/HTS-1 (HTS-1 was a titanium silicon molecular sieve), Cu0.7Mn2Y0.3Ox/HTS-1 and Cu0.7Mn2Ce0.3Ox/HTS-1 catalysts were prepared by the impregnation method. The textural properties, redox properties and acidity of the catalysts were characterized by X-ray diffractometer (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), frustrated total internal reflection (FT-IR), ammonium temperature-programmed desorption (NH3-TPD) and pyridine adsorption internal reflection (Py-IR) measurements. The potential roles of Lewis acid sites (activating dioxygen) were discussed, and the experimental results indicated that the most efficient route for toluene degradation over Cu0.7Mn2Ce0.3Ox/HTS-1 (toluene conversion rate of 90% (T99) = 295°C) was ascribed to regulation of the synergistic effects of redox properties (activating molecular toluene) and Lewis acid sites (activating dioxygen). The Mars–Van–Krevelen (MVK) model was adopted to describe the reaction process of toluene oxidation, which gave an in-depth view into the toluene degradation over CuMn2O4/HTS-1, Cu0.7Mn2Y0.3Ox/HTS-1 and Cu0.7Mn2Ce0.3Ox/HTS-1. In addition, the synergistic effects between redox properties and Lewis acid sites were studied in detail.
