Dataset Information

Hydrogenation of Toluene to Methyl Cyclohexane over PtRh Bimetallic Nanoparticle-Encaged Hollow Mesoporous Silica Catalytic Nanoreactors.

ABSTRACT: PtRh bimetallic nanoparticle (NP)-encaged hollow mesoporous silica nanoreactors (PtRh@HMSNs) are prepared by employing metal-ion-containing charge-driven polymer micelles as templates. These nanoreactors feature ?1-2 nm PtRh NPs in ?11 nm hollow cavities of HMSNs. Among various Pt _x Rh _y @HMSNs, Pt_0.77Rh₁@HMSNs show the best catalytic performance for toluene hydrogenation. Under 30 °C, atmospheric H₂ pressure, and a toluene/(Pt+Rh) molar ratio of 200/1, Pt_0.77Rh₁@HMSNs reach 100.0% of methyl cyclohexane yield and demonstrate a much better catalytic performance than monometallic Pt@HMSNs and Rh@HMSNs and their physical mixtures. Moreover, Pt_0.77Rh₁@HMSNs exhibit a good catalytic stability during recycling experiments. The enhanced performance of Pt_0.77Rh₁@HMSNs is ascribed to the interaction between Pt and Rh, the beneficial effect of the relatively large mesoporous channels for mass transfer, as well as the confinement effect of functional NPs inside hollow cavities.

SUBMITTER: Li K

PROVIDER: S-EPMC7931421 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Hydrogenation of Toluene to Methyl Cyclohexane over PtRh Bimetallic Nanoparticle-Encaged Hollow Mesoporous Silica Catalytic Nanoreactors.

Li Kaijie K An Heliang H Yan Peijian P Yang Caoping C Xiao Tao T Wang Junyou J Zhou Shenghu S

ACS omega 20210215 8

PtRh bimetallic nanoparticle (NP)-encaged hollow mesoporous silica nanoreactors (PtRh@HMSNs) are prepared by employing metal-ion-containing charge-driven polymer micelles as templates. These nanoreactors feature ∼1-2 nm PtRh NPs in ∼11 nm hollow cavities of HMSNs. Among various Pt x Rh y @HMSNs, Pt0.77Rh1@HMSNs show the best catalytic performance for toluene hydrogenation. Under 30 °C, atmospheric H2 pressure, and a toluene/(Pt ...[more]

PMID: 33681623

Similar Datasets

Project description:Bovine viral diarrhoea virus 1 (BVDV-1) is arguably the most important viral disease of cattle. It is associated with reproductive, respiratory and chronic diseases in cattle across the world. In this study we have investigated the capacity of the major immunological determinant of BVDV-1, the E2 protein combined with hollow type mesoporous silica nanoparticles with surface amino functionalisation (HMSA), to stimulate immune responses in sheep. The current work also investigated the immunogenicity of the E2 nanoformulation before and after freeze-drying processes. The optimal excipient formulation for freeze-drying of the E2 nanoformulation was determined to be 5% trehalose and 1% glycine. This excipient formulation preserved both the E2 protein integrity and HMSA particle structure. Sheep were immunised three times at three week intervals by subcutaneous injection with 500 μg E2 adsorbed to 6.2 mg HMSA as either a non-freeze-dried or freeze-dried nanoformulation. The capacity of both nanovaccine formulations to generate humoral (antibody) and cell-mediated responses in sheep were compared to the responses in sheep immunisation with Opti-E2 (500 μg) together with the conventional adjuvant Quil-A (1 mg), a saponin from the Molina tree (Quillaja saponira). The level of the antibody responses detected to both the non-freeze-dried and freeze-dried Opti-E2/HMSA nanoformulations were similar to those obtained for Opti-E2 plus Quil-A, demonstrating the E2 nanoformulations were immunogenic in a large animal, and freeze-drying did not affect the immunogenicity of the E2 antigen. Importantly, it was demonstrated that the long term cell-mediated immune responses were detectable up to four months after immunisation. The cell-mediated immune responses were consistently high in all sheep immunised with the freeze-dried Opti-E2/HMSA nanovaccine formulation (>2,290 SFU/million cells) compared to the non-freeze-dried nanovaccine formulation (213-500 SFU/million cells). This study is the first to demonstrate that a freeze-dried silica mesoporous nanovaccine formulation gives balanced immune responses in a production animal.

Project description:Tunable glutathione (GSH)-sensitive hollow mesoporous silica nanoparticles (HMSiO2 NPs) were developed using a structural difference-based selective etching strategy. These organosilica hollow nanoparticles contained disulfide linkages (S-S) in the outer shell which were degraded by GSH. The particles were compared with their nonGSH-sensitive tetraethyl orthosilicate (TEOS) HMSiO2 counterparts in terms of their synthesis method, characterization, doxorubicin (DOX) release profile, and in vitro cytotoxicity in MCF-7 breast cancer cells. Transmission electron microscopy (TEM) of the particles indicated that the fabricated HMSiO2 NPs had an average diameter of 130?±?5?nm. Thermogravimetric analysis (TGA) revealed that GSH-sensitive particles had approximately 5.3% more weight loss than TEOS HMSiO2 NPs. Zeta potential of these redox-responsive particles was -23?±?1?mV at pH?6 in deionized (DI) water. Nitrogen adsorption-desorption isotherm revealed that the surface area of the hollow mesoporous nanoreservoirs was roughly 446?±?6?m2?g-1 and the average diameter of the pores was 2.3?±?0.5?nm. TEM images suggest that the nanoparticles started to lose mass integrity from Day 1. The particles showed a high loading capacity for DOX (8.9?±?0.5%) as a model drug, due to the large voids existing in the hollow structures. Approximately 58% of the incorporated DOX released within 14?days in phosphate buffered saline (PBS) at pH?6 and in the presence of 10?mM of GSH, mimicking intracellular tumor microenvironment while release from TEOS HMSiO2 NPs was only c.a. 18%. The uptake of these hollow nanospheres by MCF-7 cells and RAW 264.7 macrophages was evaluated using TEM and confocal microscopy. The nanospheres were shown to accumulate in the endolysosomal compartments after incubation for 24?h with the maximum uptake of c.a. 2.1?±?0.3% and 5.2?±?0.4%, respectively. Cytotoxicity of the nanospheres was investigated using CCK-8 assay. Results indicate that intact hollow particles (both GSH-sensitive and TEOS HMSiO2 NPs) were nontoxic to MCF-7 cells after incubation for 24?h within the concentration range of 0-1000??g?ml-1. DOX-loaded GSH-sensitive nanospheres containing 6??g?ml-1 of DOX killed c.a. 51% of MCF-7 cells after 24?h while TEOS HMSiO2 NPs killed c.a. 20% with the difference being statistically significant. Finally, cytotoxicity data in RAW 264.7 macrophages and NIH 3?T3 fibroblasts shows that intact GSH-sensitive HMSiO2 NPs did not show any toxic effects on these cells with the concentrations equal or <125??g?ml-1.

Dataset Information

Hydrogenation of Toluene to Methyl Cyclohexane over PtRh Bimetallic Nanoparticle-Encaged Hollow Mesoporous Silica Catalytic Nanoreactors.

Publications

Hydrogenation of Toluene to Methyl Cyclohexane over PtRh Bimetallic Nanoparticle-Encaged Hollow Mesoporous Silica Catalytic Nanoreactors.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets