Xiangyu Wang

Effect of Addition of Base on Ceria and Reactivity of CuO/CeO2 Catalysts for Low-Temperature CO Oxidation

Abstract In this work, we have reported the influence of the addition of base (KOH) on the physic-ochemical property of ceria synthesized by alcohothermal process, and the alcohothermal mechanism was also put forward. Furthermore, the prepared CeO 2 was used as the support to prepare CuO/CeO 2 catalysts via the wet impregnation method. The samples were characterized by N 2 adsorption-desorption, X-ray powder diffraction (XR.D), high resolution transmission electron microscopy (HRTEM), and temperature-programmed reduction by Eb (H 2 -TPR). The catalytic properties of the CuO/CeO 2 catalysts for low-temperature CO oxidation were studied using a microreactor-GC system. The crystal size of CeO 2 -A was much smaller than that of CeO 2 -B, and the corresponding copper oxide catalysts exhibited higher catalytic activity than that of the CeO 2 -B-supported catalysts under the same reaction conditions. The alcohothermal mechanism indicated that KOH plays a key role in determining the physicochemical and catalytic properties of ceria-based materials.

Direct synthesis, characterization and catalytic performance of Al-SBA-15 mesoporous catalysts with varying Si/Al molar ratios

Through a directly hydrothermal process and utilizing Pluronic P123 triblock polymer (EO20PO70EO20, Mavxa0=xa05800) as a template, Al-SBA-15 mesoporous materials have been prepared with different Si/Al molar ratios. The materials were characterized by XRD, ICP-OES, SEM, TEM, Py FT-IR, N2 adsorption–desorption and NH3-TPD techniques. Meanwhile, the catalytic performance of the Al-SBA-15 materials was investigated through Friedel–Crafts alkylation of 2,4-ditert-butyl-phenol with cinnamyl alcohol. Characterization results showed that the catalysts contain a variety of acid sites whose contents vary in a systematic manner with various Si/Al molar ratios of the materials, and have a higher catalytic activity in the alkylation reaction of phenol with tert-butanol. It was found that the Al-SBA-15 samples with good mesoporous structure are highly reusable preserving most of their catalytic activity after five cycles.