Influence of sodium-modified Ni/SiO catalysts on the tunable selectivity of CO hydrogenation: Effect of the CH selectivity, reaction pathway and mechanism on the catalytic reaction.

CO hydrogenation over Ni/SiO catalysts with and without Na additives was investigated in terms of the catalytic activity, selectivity of CO methanation and reaction mechanism. Na additives could cause the formation of NaO species that might deposit on the Ni surface of Ni/SiO (NiNa/SiO). When the Ni metal is partially covered with NaO species, a highly positive charge on the Ni metal could occur compared to the original Ni/SiO catalyst.

Tiny Ni particles dispersed in platelet SBA-15 materials induce high efficiency for CO methanation.

In this study, short-channel SBA-15 with a platelet morphology (p-SBA-15) is used to support Ni to effectively enhance catalytic activity and CH selectivity during CO hydrogenation. The use of p-SBA-15 as a support can result in smaller Ni particle sizes than Ni particles on typical SBA-15 supports because p-SBA-15 possesses a larger surface area and a greater ability to provide metal-support interactions. The Ni/p-SBA-15 materials with tiny Ni particles exhibit enhanced catalytic activity toward CO hydrogenation and CH formation during CO hydrogenation compared to the same Ni loading on a SBA-15 support.

Au Nanoparticles Deposited on Magnetic Carbon Nanofibers as the Ultrahigh Sensitive Substrate for Surface-Enhanced Raman Scattering: Detections of Rhodamine 6G and Aromatic Amino Acids.

Surface-enhanced Raman scattering (SERS) is a unique spectroscopy that can offer high-sensitive detection for many molecules. Herein, the Au particles deposited on carbon nanofiber-encapsulated magnetic Ni nanoparticles (NPs) (Ni@CNFs@Au) have been successfully synthesized for SERS measurements. The Ni@CNFs@Au substrates have the advantages of a high SERS sensitivity and good magnetic response.

Decomposition of Large Cu Crystals into Ultrasmall Particles Using Chemical Vapor Deposition and Their Application in Selective Propylene Oxidation.

In this work, we report a novel application of chemical vapor deposition (CVD) in which the calcination and reduction of Cu(thd) deposited onto 4.9 wt % Cu/SiO induces significant decomposition of 28 nm crystalline Cu into ultrasmall ∼2 nm particles (5.1 wt % Cu/SiO).

Ni Nanoparticles Supported on Cage-Type Mesoporous Silica for CO2 Hydrogenation with High CH4 Selectivity.

Ni nanoparticles (around 4 nm diameter) were successfully supported on cage-type mesoporous silica SBA-16 (denoted as Ni@SBA-16) via wet impregnation at pH 9, followed by the calcination-reduction process. The Ni@SBA-16 catalyst with a very high Ni loading amount (22.9 wt %) exhibited exceptionally high CH4 selectivity for CO2 hydrogenation.

Synthesis of sub-nanosized Pt particles on mesoporous SBA-15 material and its application to the CO oxidation reaction.

In this work, we show that the size and shape of Pt nanoparticles in SBA-15 can be controlled through vacuum and air calcination. The vacuum-calcination/H2-reduction process is used to thermally treat a 0.2 wt% Pt(4+)/SBA-15 sample to obtain small 2D clusters and single atoms that can significantly increase Pt dispersion in SBA-15.

One-step preparation of hydrophilic carbon nanofiber containing magnetic Ni nanoparticles materials and their application in drug delivery.

A one-step process for the synthesis of hydrophilic carbon nanofibers (CNFs) through CO2 hydrogenation on NiNa/Al2O3 was developed for the loading and targeted delivery of the anticancer drug doxorubicin (DOX). CNFs that were synthesized on NiNa/Al2O3 for 9 h at 500 °C exhibited an adequate magnetic response and a large content of hydrophilic oxygen-containing functional groups on the carbon surface, resulting in excellent colloidal solution. The CNF material exhibited a highly efficient capacity for DOX adsorption, particularly at pH 9.

Ethane-bridged periodic mesoporous organosilicas functionalized with high loadings of carboxylic acid groups: synthesis, bifunctionalization, and fabrication of metal nanoparticles.

Well-ordered periodic mesoporous organosilicas (PMOs) functionalized with high contents of carboxylic acid (COOH) groups, up to 85 mol % based on silica, were synthesized by co-condensation of 1,2-bis(triethoxysilyl)ethane (BTEE) and carboxyethylsilanetriol sodium salt (CES) under acidic conditions by using alkyl poly(oxyethylene) surfactant Brij 76 as a structure-directing agent. A variety of techniques including powder X-ray diffraction (XRD), nitrogen adsorption/desorption, Fourier-transformed infrared (FTIR), transmission electron microscopy (TEM), (13) C- and (29) Si solid-state nuclear magnetic resonance (NMR) were used to characterize the products. The materials thus obtained were used as an effective support to synthesize metal nanoparticles (Ag and Pt) within the channel of 2D hexagonal mesostructure of PMOs.

Sulphate-activated growth of bamboo-like carbon nanotubes over copper catalysts.

A sulphate-activated mechanism is proposed to describe the growth of bamboo-like carbon nanotubes (CNTs) over copper catalysts using chemical vapour deposition with helium-diluted ethylene. Sulphate-assisted copper catalysts afford a high-yield growth of bamboo-like CNTs at a mild temperature, 800 °C; however, non-sulphate-assisted copper catalysts, e.g.

Synthesis of Cu nanoparticles in mesoporous silica SBA-15 functionalized with carboxylic acid groups.

In this study, the mesoporous silica SBA-15 materials containing carboxylic acid groups were used as an effective support to synthesize Cu nanoparticles. Various Cu loading levels from 4% to 13% on SBA-15 catalysts produced an average particle size of 2.8 to 3.

Self-assembly formation of multi-walled carbon nanotubes on gold surfaces.

We report on the observation of self-assembled carbon nanostructures on a standard transmission electron microscopy (TEM) Au substrate formed via thermal chemical vapor deposition. Multi-walled carbon nanotubes (MWNTs) and other carbon nanostructures (CNs), such as carbon nanofibers and carbon nanoparticles (NPs), could be fabricated through structural transformation of metastable carbon layers on the Au surface during 800-850 °C with the thermal decomposition of ethylene. At these temperatures, we found that Au NPs will form immediately through the structural transformation of the Au grid surface in helium atmosphere.

Low-temperature water gas shift reaction on Cu/SiO2 prepared by an atomic layer epitaxy technique.

An atomic layer epitaxy technique was used to produce nanoscale 2.9-3.4 nm copper particles supported on silica, and the nanoscale Cu/SiO2 catalysts can show surprisingly high activity for the water gas shift reaction, in comparison with the 5.