Li Yue,Guangci Li,Feng Zhang,Lei Chen,Xuebing Li,Xiang Huang
A series of CoMoO 4 hydrates composed of nanorods have been synthesized with different alcohol–water solvent systems, and the corresponding Co–Mo sulfides are obtained after sequential calcination and sulfurization. The characterization results show the change in solvent system can efficiently adjust the particle size of the Co–Mo precursors, while cannot affect their components and morphologies. Because of the different particle size, the specific surface areas (SSA) of the final Co–Mo sulfides are different. The particles with small size can lead to a high SSA that benefits the exposure and dispersion of active components, and further promote the incorporation of MoS 2 slabs with Co atoms to form “Co–Mo–S” structures on the surface of the sulfides. More “Co–Mo–S” structures would create more coordinative unsaturated sites with high activity in situ during hydrodesulfurization (HDS) reaction, resulting in a higher HDS activity. Among the Co–Mo sulfides, since S-m/w derived from methanol–water system possesses the smallest particle size and the most active sites, it naturally exhibits the highest HDS activity toward dibenzothiophene.
In order to explore the influence of wood types on formation of polycyclic aromatic hydrocarbons (PAHs) in traditional smoked and grilled meat products, the effect of lignin in woods on formation of PAHs was investigated in meat model systems. The results showed that PAHs formation was much dependent on the heating conditions. The addition of lignin led to significantly increased PAHs, which being connected with lignin structure. In comparison, the formation of PAHs was more facilitated by lignin with G structure than that with G/S structure. However, further study of adding lignin precursors demonstrated that lignin precursors with S structure were more favorable to the formation of PAHs than those with G structure. It was proposed that the relative content and activity of G/S structure of lignin in wood played a significant role in the formation of PAHs, which might provide theoretical reference for inhibition of PAHs fundamentally.