Siwen Li

Photocatalytic oxidation desulfurization of model diesel over phthalocyanine/La0.8Ce0.2NiO3

A series highly efficient and stable metallophthalocyanine/La0.8Ce0.2NiO3 (ML/LCNO) photocatalysts were prepared by a facile sol-gel and immersion method. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), TEM, N2 adsorption-desorption, and UV-Vis. The results revealed that LCNO calcined at 700°C possessed a perovskite structure with porous, and phthalocyanine not only adsorbed on the surface but also loaded in the pores of the LCNO oxide. The photocatalytic activities of the samples were evaluated by the photocatalytic oxidation of dibenzothiophene (DBT) under simulated sunlight irradiation. It was found that either macrocyclic structure or center metal of phthalocyanine had great influences on the photocatalytic activity of ML/LCNO. The oxidative reactivity of the different macrocycles was found in the order of MPc/LCNO>MTAP/LCNO>MPTpz/LCNO; which of different center metals was CoL/LCNO>FeL/LCNO>MnL/LCNO>NiL/LCNO>CuL/LCNO. The catalysts were reused several times with a slight decrease in activity. Furthermore, this kinetics of photocatalytic oxidation of DBT indicated that the reaction was a pseudo-first-order reaction.

Preparation of mesoporous Cs-POM@MOF-199@MCM-41 under two different synthetic methods for a highly oxidesulfurization of dibenzothiophene

Two different synthetic methods, the direct method and the substitution method, were used to synthesize the Cs-POM@MOF-199@MCM-41 (Cs-PMM), in which the modified heteropolyacid with cesium salt has been encapsulated into the pores with the mixture of MOF and MCM-41. The structural properties of the as-prepared catalysts were characterized using various analytical techniques: powder X-ray diffraction, FT-IR, SEM, TEM, XPS and BET, confirming that the Cs-POM active species retained its Keggin structure after immobilization. The substitution method of Cs-PMM exhibited more excellent catalytic performance for oxidative desulfurization of dibenzothiophene in the presence of oxygen. Under optimal conditions, the DBT conversion rate reached up to 99.6% and could be recycled 10 times without significant loss of catalytic activity, which is mainly attributed to the slow leaching of the active heteropolyacid species from the strong fixed effect of the mixture porous materials.

Synthesis and catalytic activity to Li/SOCl2 battery of asymmetric and symmetric binuclear metal phthalocyanines

In our present work, the asymmetric and symmetric binuclear metal phthalocyanines (M2(PcTN)2 and M2(PcTN)2S), battery catalysts, were synthesized through microwave reaction and characterized by EA, IR and UV-vis spectroscopy. Their catalytic activity in the Li/SOCl2 battery was evaluated by adding right amount catalysts into the electrolyte. The results indicated that the capacity of the catalyzed battery increased by 6.74–67.26% and 13.41–84.36%, and the energy increased by 9.29–65.72% and 14.77–88.15% respectively, compared with the battery without phthalocyanines.

Synthesis, characterization, and mechanism studies of bis(imino)pyridine ligands and their Cr(III) compounds

Two new bis(imino)pyridine ligands L1, L2 (L1 = 2,6-bis[1-(4-bromophenylimino)]pyridine, L2 = 2,6-bis[1-(4-methylphenylimino)]pyridine) have been prepared. Their compounds [CrCl3L1] (I) and [Cr(Cl)(μ-Cl)(L2′)]2 (II) (L2′ = 6-bis(6-methylquinoline)pyridine) for olefin oligomerization were obtained by hydrothermal methods, during which L2′ was appeared from L2, and characterized by elemental analysis, single-crystal X-ray analysis (CIF files CCDC nos. 1025448 (I),1025447 (II)), IR spectra and melting point test. Compound I is a mononuclear compound, while compound II, bridged with the chlorine atoms, is a binuclear compound. The transformation mechanism between L2 and L2′ is also studied, and the possible reason is due to the presence of the electron-donating groups as substituents on L2. The subsequent studies on that will be carried on.