Mesoporous zeolite ZSM-5 (ZSM-5-M) was synthesized and used as support for the preparation of highly efficient nickel phosphide catalyst (Ni2P/ZSM-5-M) in the deep hydrogenation of phenanthrene and in the hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DM-DBT). Compared with Ni2P catalysts supported silica and high surface area hexagonal mesoporous silica (HMS) (Ni2P/SiO2 and Ni2P/HMS), Ni2P/ZSM-5-M exhibits higher hydrogenation and HDS activity. The phenanthrene conversion and deep hydrogenation products selectivity over Ni2P/ZSM-5-M (95% and 83%) are much higher than those over Ni2P/SiO2 (61% and 73%) and Ni2P/HMS (69% and 45%) under mild conditions. The 4,6-DM-DBT conversion over Ni2P/ZSM-5-M (93%) was higher than that over Ni2P/SiO2 (62%). This feature is attributed to the difference in surface properties of support. A large amount of acidic hydroxyl groups on the zeolites can interact strongly with catalyst precursor, resulting in the formation of highly dispersed Ni2P particles with small sizes, which provide abundant hydrogenation active sites.

Zeolite Y nanoparticle assemblies (Y-NA) with a mesoporous structure were directly synthesized at 75 °C for 16 h without adding any organic templates. The changes in structure, morphology and textural parameters of the materials obtained after different crystallization times were investigated via powder X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2-sorption. The results show that Y-NA had a micro–mesoporous structure composed of highly crystalline particle assemblies with sizes of 400–900 nm. The H-form Y-NA (HY-NA) is strongly acidic, and exhibits a good catalytic performance in the Ritter reaction, as compared with the H-form microporous zeolite Y and mesoporous zeolite ZSM-5.

•A composite (AZ-M-x) was prepared by mixing mesoporous zeolite ZSM-5 and γ-Al2O3.•Mixing mesoporous zeolite ZSM-5 into γ-Al2O3 weakens the Mo-support interaction.•Multi-stacked MoS2 active phases are easily formed on the CoMoS/AZ-M-x catalyst.•CoMoS/AZ-M-x catalyst exhibits high intrinsic activity in the HDS of 4,6-DMDBT.Composite materials (AZ-M-x) were prepared by mechanically mixing the mesoporous zeolite ZSM-5 (MZSM-5) and γ-Al2O3. This composite was employed as a support for CoMo catalysts (CoMoS/AZ-M-x). The CoMoS/AZ-M-x catalysts show high activity (TOF = 2.1–3.0 × 10− 3 s− 1) in the hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) as compared to the CoMo catalyst supported on γ-Al2O3 (CoMoS/γ-Al2O3, TOF = 1.9 × 10− 4 s− 1), and the HDS activity increased with the MZSM-5 content in the composites. In contrast, the HDS activity of a mixture of microporous ZSM-5 with γ-Al2O3 supported CoMo catalyst is similar to that of the CoMoS/γ-Al2O3 catalyst. Compared with microporous ZSM-5, introducing MZSM-5 into γ-Al2O3 improves the mesoporous structure of the composites, which benefits mass transfer of the reactant molecules. Furthermore, MZSM-5 in the composites modifies their surface properties with abundant acidic hydroxyl groups, which can weaken the Mo-support interaction, leading to modifications in the morphology of the MoS2 phases to form multi-stacked MoS2 active phases on the CoMoS/AZ-M-x catalysts.Download high-res image (173KB)Download full-size image

Zeolite Y nanosheets with a micro–meso–macroporous structure were synthesized, and applied in the assembly of a Pd catalyst (Pd/NS-Y) for direct vinylation of thiophenes with high activity and selectivity, as compared to Pd(OAc)2, Pd(NO3)2, and Pd(PPh3)4 catalysts. This feature should be assigned to the highly dispersed Pdδ+ (δ < 2) species in Pd/NS-Y, which are more active than Pd2+.

A strong acidic zeolite Y nanoparticle assembly (HNANO-Y) with a micro–meso–macroporous structure was synthesized and used as a highly efficient heterogeneous catalyst for the hydration of alkynes to prepare ketone compounds, as compared to acidic mesoporous zeolite ZSM-5 and Beta catalysts. This feature should be assigned to the fact that the micro–meso–macroporous structure in the HNANO-Y benefits mass transfer and the strongly acidic sites on HNANO-Y facilitate alkyne hydration activity. The catalyst can be reused six times without loss of activity.

Developing highly active heterogeneous catalyst with strong basicity and porous structure is a highly attractive strategy for the base-catalyzed organic chemistry. Herein, we directly synthesized the mesoporous zeolite ETS-10 (METS-10) from using a water glass contained cationic copolymer with quaternary ammonium groups as a template. Furthermore, when the nickel nitrate solution was added into the starting synthesis gel, the nickel species facilitated the mesopore formation, and the Ni-containing mesoporous zeolite ETS-10 (Ni-METS-10) was obtained. Catalytic test results showed that the conversions of the benzaldehyde and citral over Ni-METS-10 (88.8 and 63.2 %) and METS-10 (85.5 and 60.1 %) catalysts are higher than those over both mesopore-free ETS-10 (77.3 and 47.7 %) and mesoporous NaX (MNaX, 55.0 and 35.2 %) catalysts in the condensation reactions with ethyl cyanoacetate. The higher activity of METS-10 and Ni-METS-10 than ETS-10 and MNaX is assigned to the fact that the strong basic sites on the catalysts can activate the reaction substrate and the mesoporous in the catalyst benefit the mass transfer and enhance the catalytic activity.

A Cu-doped zeolite ZSM-5 (Cu-ZSM-5-M) with a micro-meso-macroporous structure was directly synthesized, and it exhibits excellent catalytic activity and good recyclability in the cross-coupling of aryl halides with diphenyl disulfides. This feature should be attributed to the structural characteristics of meso-macropores and homogeneous dispersion of active Cuδ+ (δ < 2) species in Cu-ZSM-5-M.

A magnesium oxide nanosheet assembly (NS-MgO) with high surface area (255 m2/g) and nanopore volume (0.30 cm3/g) was prepared by a pressure-assisted carbonation method at large scale. After loading of cobalt and molybdenum (CoMo) species and followed by sulfidation, the NS-MgO supported CoMo catalyst (Co-MoS2/NS-MgO) exhibits high activity (94.2%) and good nitrogen tolerance in the hydrodesulfurization (HDS) of dibenzothiophene (DBT), compared with a conventional γ-alumina-supported CoMo catalyst (64.1%). These results are attributed to the difference in the basicity of the NS-MgO and γ-Al2O3 supports. The large amount of the middle strong basic sites on NS-MgO can avoid the polymerization of Mo species and form small Mo oxide clusters. After sulfidation, the small MoS2 clusters with shorter lengths and less stacking formed on the NS-MgO contribute to an increase in the sites available for Co promotion, resulting in the Co-MoS2/NS-MgO catalyst with high HDS activity.

Zeolite nanofiber assemblies (HNB-MOR) as efficient heterogeneous catalysts for the formation of a range of acetals in good yields. The mesoporosity of HNB-MOR benefits mass transfer, and the strong acidic sites on HNB-MOR facilitate acetalization activity. The catalyst can be reused 10 times without loss of activity.

Developing a low-cost route to synthesize mesoporous TS-1 (MTS-1) is of great importance because of its practical application in industry. Herein, we first synthesized a copolymer containing quaternary ammonium groups by a mesoporous template comprising inexpensive starting materials. Subsequently, waterglass (sodium metasilicate), TiCl3, and copolymer were dispersed in the preformed seeds emulsion, resulting in a gel for synthesizing MTS-1. The counterpart material (CTS-1) was also synthesized by the same procedure except for the absence of the copolymer. Compared with CTS-1, the MTS-1 exhibits good crystallinity and well-defined tetrahedral coordinated Ti species (TiIV) in the framework as well as excellent catalytic activity in the oxidation of bulky molecules, such as dibenzothiophene and benzyl phenyl sulfide. This feature may be attributed to the fact that the quaternary ammonium groups on copolymer facilitates the formation of the MFI structure and energetically incorporates the Ti species into the framework.

Developing highly active hydrodesulfurization (HDS) catalysts is of great importance for producing ultraclean fuel. Herein we report on crystalline mordenite nanofibers (NB-MOR) with a bundle structure containing parallel mesopore channels. After the introduction of cobalt and molybdenum (CoMo) species into the mesopores and micropores of NB-MOR, the NB-MOR-supported CoMo catalyst (CoMo/NB-MOR) exhibited an unprecedented high activity (99.1%) as well as very good catalyst life in the HDS of 4,6-dimethyldibenzothiophene compared with a conventional γ-alumina-supported CoMo catalyst (61.5%). The spillover hydrogen formed in the micropores migrates onto nearby active CoMo sites in the mesopores, which could be responsible for the great enhancement of the HDS activity.

•Small and highly dispersed Ni2P nanoparticles on MZSM-5 were prepared by adding citric acid (CA).•The mechanism of formation of small Ni2P particles with CA assistance was investigated.•Small Ni2P particles on MZSM-5 exhibit high hydrogenation activity.Preparing small, highly dispersed Ni2P particles is important for improving the hydrogenation ability of Ni2P. Here, Ni2P nanoparticles (approximately 4.3 nm) on mesoporous zeolite ZSM-5 (Ni2P/MZSM-5-CA) were prepared using citric acid (CA) as an assistant agent. The formation mechanism of small Ni2P particles when CA was added was investigated by combining UV–vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, and temperature-programmed reduction with a transmission electron microscope and CO chemisorption. The results indicated that the formed CA–Ni complex with high viscosity favors the Ni precursor dispersed on the dried catalyst. After calcination, the released Ni species strongly interacted with surface acidic hydroxyl groups on MZSM-5, leading to the formation of Ni2P particles with small sizes and good dispersion under a reducing atmosphere. The reaction rate constants and TOFs over Ni2P/MZSM-5-CA (16.2 × 10−2 μmol g−1 s−1 and 9.7 × 10−4 s−1) are much higher than over Ni2P/MZSM-5 (8.2 × 10−2 μmol g−1 s−1 and 8.3 × 10−4 s−1) in 4,6-dimethyldibenzothiophene hydrodesulfurization. In addition, Ni2P/MZSM-5-CA catalyst shows higher activity than Ni2P catalyst without CA in phenanthrene hydrogenation.Download high-res image (213KB)Download full-size image

Zeolite Y nanosheets with a micro–meso–macroporous structure were synthesized, and applied in the assembly of a Pd catalyst (Pd/NS-Y) for direct vinylation of thiophenes with high activity and selectivity, as compared to Pd(OAc)2, Pd(NO3)2, and Pd(PPh3)4 catalysts. This feature should be assigned to the highly dispersed Pdδ+ (δ < 2) species in Pd/NS-Y, which are more active than Pd2+.

A Cu-doped zeolite ZSM-5 (Cu-ZSM-5-M) with a micro-meso-macroporous structure was directly synthesized, and it exhibits excellent catalytic activity and good recyclability in the cross-coupling of aryl halides with diphenyl disulfides. This feature should be attributed to the structural characteristics of meso-macropores and homogeneous dispersion of active Cuδ+ (δ < 2) species in Cu-ZSM-5-M.