Synthesis of Carbon Nanofiber-Titania-Cordierite Monolith Composite and Its Application as Catalyst Support On Citral Hydrogenation

摘要

We reported the synthesis of a promising carbon nanofiber-titania-cordierite monolith composite (C/TiO_2/monolith) and its application in citral hydrogenation. The composite was synthesized through two steps: TiO_2 coating on the surface of the monolith with sol-gel method and the following carbon deposit by methane decomposition. C/TiO_2/monolith was subsequently employed to prepare its supported palladium catalyst, Pd/C/TiO_2/monolith and its catalytic performance was evaluated in selective hydrogenation of citral. Results revealed that 2.0 wt% tetrabutyl titanate sol in composite synthesis was the best in improving textural properties of C/TiO_2/monolith. The optimal composite possessed a BET surface area of 39.4 m~2/g and micropore area accounted for only 3.8% of its total BET surface area. It contained about 30 wt% of carbon, which was mainly composed of carbon nanofiber. Pd/C/TiO_2/monolith exhibited the high citronellal selectivity (81%) at 90% citral conversion, which was attributed to the decrease of internal diffusion limitation due to its mesoporous structure.