One-pot deposition of palladium on hybrid TiO2 nanoparticles and catalytic applications in hydrogenation

Low-Temperature O3 Decomposition over Pd-TiO2 Hybrid Catalysts

In aircraft and spacecraft, outside air is not directly fed to the passenger because it contains ozone at elevated altitudes. The decomposition of low concentration ozone in the air was carried out at 25 °C by catalytic oxidation on Pd-based catalysts supported on a high surface area hybrid TiO2. The use of these hybrid catalysts has shown a beneficial effect, both on the catalytic activity and on the catalyst stability. Kinetic studies showed that the most promising catalytic phase (Pd/TiO2_100) was the one obtained from the TiO2 support containing the lowest content of citrate ligands and leading to small Pd particles (around 4 nm). The effect of catalyst synthesis on the decomposition of O3 gas (15 ppm) in a dry and humid (HR = 10%) stream in a closed environment such as aircraft or spacecraft was also investigated in this study and further elucidated by detailed characterizations. It was shown that the system could be used as an effective treatment for air coming from outside.

Molecular Engineering of Metal Alkoxides for Solution Phase Synthesis of High-Tech Metal Oxide Nanomaterials

The 'bottom-up' synthesis of inorganic nanomaterials with precision at the atomic/molecular level offers many opportunities for the design and improvement of the nanomaterials for various applications. Molecular engineering during soft chemical processing for the synthesis of functional nanomaterials enables the desired chemical and physical properties of the precursors, such as solubility or volatility, clean decomposition, control of stoichiometry for multimetallic species to name a few, and leads to easy control of uniform particle size distribution, stoichiometry…. This Minireview illustrates some important aspects of the molecular engineering in light of some recent developments from the molecular synthesis of nanomaterials involving non-silicon metal alkoxide systems for high-tech applications.

Facile preparation of porous In2TiO5-rutile composite nanotubes by electrospinning and sensitivity enhancement in NO2 gas at room temperature

Porous In2TiO5-rutile composite nanotubes (IRCNs) were synthesized via a facile one-step synthesis of the electrospinning approach by using tetrabutyl titanate (TBT), indium nitrate, and polyvinylpyrrolidone (PVP) as a soft-template followed by two-step calcination. The porous composite nanotubes with a bigger surface area have single-crystalline rutile with (110) crystal plane, and the sensor fabricated by it with a content of 12.5 at% In2TiO5 (IRCN2) has shown a response of 4.04 to 100 ppm NO2 at room temperature (RT), which was 20 times as high as the pure In2TiO5 sensor under the same conditions. The IRCN2 sensor had excellent selectivity compared with other gas species such as CO, H2, NH3, H2S and CH4 at RT. The enhanced sensing properties were attributed to the synergy of integrated In2TiO5 and rutile, heterojunction of single-crystal, and its nanotubular structure. Hence, the IRCN2 sensor has a potential application for the development of novel gas sensors at RT.

High performance Pd catalyst using silica modified titanate nanotubes (STNT) as support and its catalysis toward hydrogenation of cinnamaldehyde at ambient temperature

A Pd/STNT catalyst, with silica modified titanate nanotubes as support, exhibited significantly enhanced activity towards hydrogenation of cinnamaldehyde.

PHOTOCHEMICAL FABRICATION OF TRANSITION METAL NANOPARTICLES USING CdS TEMPLATE AND THEIR CO-CATALYSIS EFFECTS FOR TiO2 PHOTOCATALYSIS

Transition metal nanoparticles were prepared by chemical dissolution of CdS template from metal photodeposited CdS nanorod (length = 70–85 nm and width = 5–6 nm) heterocomposites. Size (9–10 nm) of metal nanoparticles obtained after CdS removal was larger than the size (4–6 nm) of metal nanodeposits over CdS template. The obtained Au nanoparticles displayed a broad red shifted absorption band at 660 nm, whereas Pt , Pd and Rh nanoparticles exhibit featureless absorption spectra. Elemental analysis confirms the complete removal of CdS template from Au – CdS ( Au — 2.65 at.%) and Ag – CdS ( Ag — 2.06 at.%) composites showing no Cd peak. These metal nanoparticles imparted dissimilar co-catalytic activity of TiO 2 for photocatalytic degradation of salicylic acid in the order Au > Pt > Pd > Ag > Rh as a function of their nature, electronegativity, redox potential and work function.