Three-dimensional Ce-MOFs-derived Ce@C-BN nanobundles for adsorptive desulfurization

Abstract

Diatomic cerium and carbon doped boron nitride (Ce@C-BN) materials derived from Ce-based metal–organic frameworks (Ce-MOFs) and boron nitride precursors were synthesized by direct single-step pyrolysis strategy. In such a strategy, Ce-MOFs not only provide a Lewis acid Ce species but also act as a carbon source to introduce more active sites. The physicochemical characteristics of resulting Ce@C-BN materials were characterized. The as-synthesized Ce@C-BN materials had a high specific surface area from microporous and mesoporous structures, and an electron transfer that enhanced the Lewis acid-base interaction between Ce and BN. The Ce@C-BN adsorbent showed a high dibenzothiophene (DBT) adsorptive capacity of 48.0 mg S/g and excellent adsorptive performance for both 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The adsorption of DBT onto Ce@C-BN followed the pseudo-second-order kinetic and Freundlich isotherm models. The improved performance of Ce@C-BN in the adsorptive desulfurization is attributed to the enhanced Lewis acid-base interaction, increased chemisorption sites via valency forces, S-Ce, and π-π interactions. Therefore, this preparation strategy of Ce@C-BN provides a novel and promising route for the development of high-performance adsorbents.