Oxidation of Benzyl Alcohol over Nitrogen-Doped Mesoporous Carbon Spheres

Document Type : Original Article

Authors

Department of Chemistry, Isfahan University of Technology, Isfahan, Iran

Abstract

In this study, the oxidation of benzyl alcohols to aldehydes using nitrogen-doped mesoporous carbon spheres as a heterogeneous catalyst was investigated for the first time. Initially, Stöber method was used to synthesize silicate-polyaminophenol-formaldehyde structures using tetraethyl orthosilicate, 3-aminophenol, and ethylene diamine as silica templates, carbon precursors, and regulators, respectively, in an aqueous-ethanol medium with ammonia as a catalyst. The synthesized structure transformed into N-doped carbon-silica structure during annealing under inert gas. N-doped mesoporous carbon spheres were formed after etching the silica network with sodium hydroxide. The amount of nitrogen loading was determined by elemental analysis, and its amount was determined to be 8.00 wt%. The surface area determined by nitrogen absorption and desorption analysis is 1186 m2g-1. Based on FE-SEM images, the average particle size is about 300 nm. Aqueous benzyl alcohol oxidation was carried out using the synthesized catalyst to investigate its catalytic activity. A study has been conducted to assess the effects of temperature, time, oxidant type, and catalyst amount on reaction yield as well as catalyst recycling potential. The synthesized catalyst shows remarkable catalytic performance for benzyl alcohol oxidation, achieving high yield (over 88% within 6 h) and selectivity (99%). The catalytic activity did not change significantly after four recycling cycles.

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