Designing efficient adsorbents for the deep removal of refractory dibenzothiophene (DBT) from fuel oil is vital for addressing environmental issues such as acid rain. Herein, zinc gluconate and urea-derived porous carbons SF-ZnNC- T ( T represents the carbonization temperature) were synthesized without solvents. Through a temperature-controlled process of “melting the zinc gluconate and urea mixture, forming H-bonded polymers, and carbonizing the polymers,” the optimal carbon, SF-ZnNC-900, was obtained with a large surface area (2280 m 2 /g), highly dispersed Zn sites, and hierarchical pore structures. Consequently, SF-ZnNC-900 demonstrated significantly higher DBT adsorption capacity of 43.2 mg S/g, compared to just 4.3 mg S/g for the precursor. It also demonstrated good reusability, a fast adsorption rate, and the ability for ultra-deep desulfurization. The superior DBT adsorption performance resulted from the evaporation of residual zinc species, which generated abundant mesopores that facilitated DBT transformation, as well as the formation of Zn-N x sites that strengthened the host-guest interaction (Δ E = -1.466 eV). The solvent-free synthesized highly dispersed Zn-doped carbon shows great potential for producing sulfur-free fuel oil and for designing metal-loaded carbon adsorbents.
Achieving selective hydrodeoxygenation of α, β-unsaturated carbonyl groups to alkenes poses a substantial challenge due to the presence of multiple functional groups. In this study, we develop a ZnNC-X catalyst (X represents the calcination temperature) that incorporates both Lewis acidic-basic sites and Zn-N x sites to address this challenge. Among the catalyst variants, ZnNC-900 catalyst exhibits impressive selectivity for alkenes in the hydrodeoxygenation of α, β-unsaturated carbonyl compounds, achieving up to 94.8% selectivity. Through comprehensive mechanism investigations and catalyst characterization, we identify the Lewis acidic-basic sites as responsible for the selective hydrogenation of C=O bonds, while the Zn-N x sites facilitate the subsequent selective hydrodeoxygenation step. Furthermore, ZnNC-900 catalyst displays broad applicability across a diverse range of unsaturated carbonyl compounds. These findings not only offer valuable insights into the design of effective catalysts for controlling alkene selectivity but also extend the scope of sustainable transformations in synthetic chemistry.