Mesoporous FDU-12 silicas with different morphologies have been synthesized under static and stirring conditions in a water bath. Furthermore, a series of mesoporous FDU-12 silicas modified by different amounts of titania have been synthesized, through a two-step method of prehydrolysis of TEOS followed by addition of titanium butoxide as a titanium precursor. Their respective NiMo supported catalysts were also prepared and characterized to elucidate the effects of titania, on the characteristics of the Mo surface species and their hydrodesulfurization (HDS) activities on dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The composites were characterized by various techniques (XRD, SEM, TEM, FT-IR, UV-vis, ²⁹Si NMR, Raman, XPS and N₂ adsorption–desorption); meanwhile, the catalysts were also tested in a higher pressure HDS reactor at T = 340 °C and P = 4 MPa with different liquid hourly space velocity (LHSV) values. The results show that the two-step synthetic route can prepare well-ordered mesoporous composites with high surface areas and large pore sizes and volumes. Obvious differences in the Mo species can be observed on the sulfided NiMo/Ti-FDU-12 catalysts. This showed that appropriate Ti loading could facilitate the dispersion of molybdena and the formation of the MoS₂ and NiMoS phases, which are the important factors for the HDS reaction. All of the catalysts presented high HDS activity, and when the Si : Ti molar ratio was increased to 5, the HDS activities on DBT and 4,6-DMDBT could reach as high as 97% and 65% respectively.

The exhaustion of fossil energy and the severe pollution induced by using plastics has forced people to embark on the road to sustainable development. The high value of the recycling of plastics has become an important part of energy conservation. Microwave treatment, owning specific interactions between the electric field and the molecules of treated materials, presents potential advantages in the application of plastic pyrolysis. Therefore, the research status of the microwave-assisted pyrolysis (MAP) of plastics to produce high-value-added liquid oil, gas, and solid carbon was reviewed in this paper. The effects of plastic properties, microwave treatment parameters, microwave absorbers, co-pyrolysis, catalysts, and reactor devices on the process and the products were analyzed. It is essential to optimize the experimental design by studying microwave-assisted co-pyrolysis technology and the application of catalysts, understanding the mechanism of co-pyrolysis to improve product selectivity. At the same time, the continuous MAP device for large-scale plastics treatment still needs to be developed. In addition, developing a large-scale simulation computing research platform for screening catalysts, optimizing processes, and commercial production is required to make the process more efficient.

Micro-mesoporous Beta-SBA-15 materials with platelet, sphere, short-rod and long-rod morphologies were in situ synthesized and used as the catalyst supports for hydro-upgrading of FCC gasoline. The characterization results revealed that the Beta-SBA-15 composites possessed both SBA-15 and Beta structures. And the materials with different morphologies exhibited different Brönsted and Lewis acid sites and pore sizes due to their corresponding synthesis conditions. The platelet Beta-SBA-15 which possessed short mesochannels with a large pore diameter had high diffusion ability. The sphere Beta-SBA-15 with more mesopore cavities, large surface area and suitable acidity exhibited outstanding isomerization and aromatization abilities. The catalytic results confirmed that the platelet CoMo/ABS-PL exhibited a high hydrodesulfurization (HDS) conversion (97.6%) while the sphere CoMo/ABS-SP catalyst showed the superior research octane number (RON) preservation ability, which were better than those of CoMo/ABS-SR (short-rod) and CoMo/ABS-LR (long-rod) catalysts. The excellent hydrodesulfurization, isomerization and aromatization abilities of CoMo/ABS-PL and CoMo/ABS-SP were attributed to the special morphology, mesochannels and appropriate acidity properties of the catalysts. Thus, the as-synthesized platelet and sphere Beta-SBA-15 materials have potential application in FCC gasoline hydro-upgrading.

A series of novel catalysts consisting of nanosized Au particles confined in micro-mesoporous ZSM-5/SBA-15 (ZSBA) materials with platelet (PL), rod (RD), and hexagonal-prism (HP) morphologies have been synthesized in situ. These catalysts possess both SBA-15 and ZSM-5 structures and exhibit excellent stability of their active sites by confinement of the Au nanoparticles (NPs) within ZSBA. The catalysts have been characterized in depth to understand their structure–property relationships. The gold NP dimensions and the pore structure of the catalysts, which were found to be sensitive to calcination temperature and synthetic conditions, are shown to play vital roles in the reduction of 4-nitrophenol. Au/ZSBA-PL, with short mesochannels (210 nm) and a large pore diameter (6.7 nm), exhibits high catalytic performance in the reduction of 4-nitrophenol, whereas Au/ZSBA-HP and Au/ZSBA-RD, with long mesochannels and relatively smaller pore sizes, show poor catalytic activities. In the case of catalysts with different gold NP sizes, Au/ZSBA-PL-350 with an Au NP diameter of 4.0 nm exhibits the highest reaction rate constant (0.14 min^-1) and turnover frequency (0.0341 s^-1). In addition, the effect of the reaction parameters on the reduction of 4-nitrophenol has been systematically investigated. A possible mechanism for 4-nitrophenol reduction over the Au/ZSBA catalysts is proposed.