Surface molecularly imprinted polymers grafted on ordered mesoporous carbon nanospheres for fuel desulfurization

Abstract

Surface molecular imprinting is an effective measure to get adsorbent materials for definite substances. In this work, ordered mesoporous carbon nanospheres (OMCNS) were prepared as carriers by a hydrothermal method with phenolic resol as the carbon source and triblock copolymer Pluronic PF127 as the soft template. A surface molecularly imprinted polymer (SMIP/OMCNS) was then obtained through a series of functionalization, grafting and elution processes with dibenzothiophene (DBT) as a template, which was designed for the deep desulfurization of fuel products by removing DBT and its derivatives. By adopting OMCNS as a carrier, SMIP/OMCNS shows excellent adsorption capacity towards DBT (218.29 mg g⁻¹), owing to the ordered mesoporous structure and high surface area of OMCNS. The better fitted pseudo-first-order model indicates that the adsorption involves mainly physical interactions, which are promoted by the mesoporous structure of OMCNS. The Langmuir and Freundlich models fitted better than the Dubinin–Radushkevich and Scatchard isothermal models did, which suggests the occurrence of both monolayer and multilayer interactions. The thermodynamics, selectivity and regenerability of SMIP/OMCNS were also investigated. The adsorption of DBT on SMIP/OMCNS proves to be an endothermic process. And the relative selectivity coefficients against benzothiophene, biphenyl and fluorine interferents reached 2.19, 2.29 and 2.37, respectively. As a result, SMIP/OMCNS can be a potential adsorbent material for deep desulfurization of fuel products and recovering DBT and its derivatives as valuable reagents for other value-added applications.