Carbon Nanofibers Grown on Anatase Washcoated Cordierite Monolith and Its Supported Palladium Catalyst for Cinnamaldehyde Hydrogenation
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- 作者：Jie Zhu ; Yong Jia ; Mingshi Li ; Mohong Lu ; Jianjun Zhu
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2013
- 出版时间：January 23, 2013
- 年：2013
- 卷：52
- 期：3
- 页码：1224-1233
- 全文大小：485K
- 年卷期：v.52,no.3(January 23, 2013)
- ISSN：1520-5045
文摘
We report the synthesis of a promising carbon nanofiber鈥搕itania鈥揷ordierite monolith composite, i.e., CNF/TiO2/monolith, and its application as catalyst support in selective hydrogenation of cinnamaldehyde (CAL) to hydrocinnamic aldehyde (HCAL). The composite was synthesized through TiO2 coating on the surface of the monolith and the following CNF growth on it. Synthesized CNF/TiO2/monolith was subsequently employed to prepare its supported palladium catalysts, Pd/CNF/TiO2/monolith. Attachment strength and acid-resistant properties of the composite have been studied to evaluate its structural stability in some severe conditions. In addition, the effects of supported Pd particles, oxygen-containing surface groups, and internal diffusion limitation on catalytic performance over Pd/CNF/TiO2/monolith were further studied. Results revealed that the total BET surface area of the composite was 31 m2/g, and the macro- and mesopore structure dominated the pore space of the material (about 93%). Meanwhile, 94% of the carbon deposit on the surface of the composite was CNF. TiO2 and CNF coating was deemed to increase its textural and acid-resistant properties. Although there is a relatively slow reaction rate over as-prepared Pd/CNF/TiO2/monolith-R due to its small BET surface area and low Pd dispersion (about 15%), the selectivity to HCAL reamined high (about 90%) over it at 95% CAL conversion, the same as that over powdered Pd/CNF (about 93%), being much higher than that over Pd/FAC (about 45%), Pd/MC, and Pd/CNF/TiO2/monolith-O (each about 82%). This was attributed to removal of acidic oxygen-containing surface groups and elimination of internal diffusion limitation on Pd/CNF/TiO2/monolith-R.