Abstract: In order to reduce the sulfur compounds in diesel fuel, boron nitride (BN) has been used as a novel metal-free catalyst in the present research. This nanocatalyst was synthesized via template-free approach followed by heating treatment at 900 ℃ in nitrogen atmosphere that the characteristics of the sample were identified by the X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and N₂ adsorption-desorption isotherms. The results of structural and morphological analysis represented that BN has been successfully synthesized. The efficacy of the main operating parameters on the process was studied by using response surface methodology based on the Box-Behnken design method. The prepared catalyst showed high efficiency in oxidative desulfurization of diesel fuel with initial sulfur content of 8040 mg·kg^-1 S. From statistical analysis, a significant quadratic model was obtained to predict the sulfur removal as a function of efficient parameters. The maximum efficiency of 72.4% was achieved under optimized conditions at oxidant/sulfur molar ratio of 10.2, temperature of 71, reaction time of 113 min, and catalyst dosage of 0.36 g. Also, the reusability of the BN was studied, and the result showed little reduction in activity of the catalyst after 10 times regeneration. Moreover, a plausible mechanism was proposed for oxidation of sulfur compounds on the surface of the catalyst. The present study shows that BN materials can be selected as promising metal-free catalysts for desulfurization process.

Key words: Desulfurization, Boron nitride (BN) nanostructure, Experimental design, Box-Behnken

摘要： In order to reduce the sulfur compounds in diesel fuel, boron nitride (BN) has been used as a novel metal-free catalyst in the present research. This nanocatalyst was synthesized via template-free approach followed by heating treatment at 900 ℃ in nitrogen atmosphere that the characteristics of the sample were identified by the X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and N₂ adsorption-desorption isotherms. The results of structural and morphological analysis represented that BN has been successfully synthesized. The efficacy of the main operating parameters on the process was studied by using response surface methodology based on the Box-Behnken design method. The prepared catalyst showed high efficiency in oxidative desulfurization of diesel fuel with initial sulfur content of 8040 mg·kg^-1 S. From statistical analysis, a significant quadratic model was obtained to predict the sulfur removal as a function of efficient parameters. The maximum efficiency of 72.4% was achieved under optimized conditions at oxidant/sulfur molar ratio of 10.2, temperature of 71, reaction time of 113 min, and catalyst dosage of 0.36 g. Also, the reusability of the BN was studied, and the result showed little reduction in activity of the catalyst after 10 times regeneration. Moreover, a plausible mechanism was proposed for oxidation of sulfur compounds on the surface of the catalyst. The present study shows that BN materials can be selected as promising metal-free catalysts for desulfurization process.

关键词: Desulfurization, Boron nitride (BN) nanostructure, Experimental design, Box-Behnken