Highly efficient catalytic removal of ethyl acetate over Ce/Zr promoted copper/ZSM-5 catalysts

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2016-02, Vol.285, p.536-543
• Main Authors: Li, Shumin, Hao, Qinglan, Zhao, Ruozhu, Liu, Deliang, Duan, Huazhen, Dou, Baojuan
• Format: Article
• Language: English
• Subjects: Catalytic oxidation; Ce/Zr promoter; CuO; Ethyl acetate
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2015.09.097

•Ce/Zr promoter addition significantly improved the catalytic activity.•Synergistic effect of Cu–Ce–Zr increased active oxygen amount and oxygen mobility.•Both reducibility and acidity played crucial roles in catalytic performance.•Optimum CuCe0.75Zr0.25/Z provided superior stability with conversion above 99.5%. A series of CuCexZr1−xOy/ZSM-5 (x=0, 0.25, 0.5, 0.75 and 1) catalysts with different Ce/Zr molar ratios were prepared by impregnation. The catalyst performances were tested for volatile organic compounds (VOCs) abatement in the fixed-bed reactor. Extensive characterizations, N2 adsorption/desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction by hydrogen (H2-TPR), were undertaken in order to correlate the morphological, structural and surface properties of CuCexZr1−xOy/ZSM-5 catalysts with their oxidation activities. The results showed that the CuO, CeO2, and ZrO2 species were highly dispersed on the surfaces of ZSM-5 support, and copper is mostly in Cu2+ state and Cu+ co-existed as well. Surface adsorbed oxygen, hydroxyl group, and oxygen vacancies were detected after the introduction of Ce and/or Zr, which increased with the increasing of Ce/Zr molar ratio. The specific surface area was not the key factor governing the catalytic activity, however, the remarkable relationship between reducibility and catalyst activity were observed. The excellent reducibility of the catalyst would lead to an improvement in catalytic performance. The optimum performance was obtained with CuCe0.75Zr0.25/Z catalyst, which offered complete conversion of ethyl acetate into CO2 at temperature as low as 270°C, the onset temperature was 110°C. Furthermore, this catalyst possessed superior stability, and no deactivation phenomenon was observed during the catalytic oxidation for 60h at 270°C.