Design of meso-TiO2@MnO(x)-CeO(x)/CNTs with a core-shell structure as DeNO(x) catalysts: promotion of activity, stability and SO2-tolerance

Preparation of novel CeMo(x) hollow microspheres for low-temperature SCR removal of NOx with NH3

A series of novel Mo doped CeO₂ hollow microspheres have been successfully synthesized using carbon microspheres as templates, which were characterized by XRD, SEM, TEM, BET and used to remove NO_x upon NH₃-SCR at lower temperature.

Structure–performance relationships of MnO2 nanocatalyst for the low-temperature SCR removal of NOX under ammonia

To investigate the corresponding relationship between catalytic efficiency and structure, MnO₂ nanomaterials (nanospheres, nanosheets, nanorods) have been prepared successfully, and were thoroughly characterized by SEM and TEM.

Morphology-dependent performance of Zr–CeVO4/TiO2 for selective catalytic reduction of NO with NH3

The morphology-dependent performance of Zr–CeVO₄/TiO₂ was demonstrated for the selective catalytic reduction of NO with NH₃.

Facile preparation of ordered mesoporous MnCo2O4 for low-temperature selective catalytic reduction of NO with NH3

Ordered mesoporous MnCo2O4 nanomaterials were successfully prepared through the nanocasting route using SBA-15 and KIT-6 as hard templates. These mesoporous nanomaterials were characterized using XRD, BET, TEM, NH3-TPD, H2-TPR, NO-TPD, XPS and DRIFT. The low temperature selective catalytic reduction (SCR) activity of NO with NH3 was investigated, which revealed that 3D-MnCo2O4 using KIT-6 as a template can totally clean all NO over a wide temperature range of 100-250 °C with a gas hourly space velocity (GHSV) of 32,000 h(-1), while 2D-MnCo2O4 with SBA-15 as a template had 95% conversion rate at the same condition. 3D-MnCo2O4 showed the best performance to clean NO due to its typical three-dimensional porous structure, large specific surface area, abundant active surface oxygen species and Lewis acid sites. All the results indicate that a novel, cheap catalyst for catalytic removal of NO can be designed by controlling the morphology at the nanoscale.

CoxC encased in carbon nanotubes: an efficient oxygen reduction catalyst under both acidic and alkaline conditions

Co_xC encased in carbon nanotubes is synthesized using a facile co-pyrolysis method and can serve as a highly efficient oxygen reduction catalyst under both acidic and alkaline conditions.

Fabrication of Mn–CeOx/CNTs catalysts by a redox method and their performance in low-temperature NO reduction with NH3

Highly active Mn–CeO_x/CNTs catalysts were first fabricated by a novel redox method, and a formation mechanism was proposed.

Obtaining a novel crystalline/amorphous core/shell structure in barium titanate nanocrystals by an innovative one-step approach

The schematic illustration showing the formation mechanism of BTO crystalline/amorphous core/shell nanocrystals induced by ultrasonication.

Rational design of 3D hierarchical foam-like Fe2O3@CuOxmonolith catalysts for selective catalytic reduction of NO with NH3

A high-performance monolith catalyst based on 3D hierarchical foam-like Fe₂O₃@CuO_xwas developed for selective catalytic reduction of NO.

Fe2O3 nanoparticles anchored in situ on carbon nanotubes via an ethanol-thermal strategy for the selective catalytic reduction of NO with NH3

Fe₂O₃ nanoparticles anchored in situ on carbon nanotubes via an ethanol-thermal strategy present an excellent DeNO_x performance.

Promoted performance of a MnOx/PG catalyst for low-temperature SCR against SO2poisoning by addition of cerium oxide

Loading of cerium oxide inhibits the formation of manganese sulfates at temperatures higher than 150 °C.

Promotion effects of SiO2 or/and Al2O3 doped CeO2/TiO2 catalysts for selective catalytic reduction of NO by NH3

A series of the CeO2-based catalysts loaded on TiO2, TiO2-SiO2, TiO2-Al2O3, and TiO2-SiO2-Al2O3 supports were prepared by incipient impregnation method for the selective catalytic reduction (SCR) of NO by NH3 in the presence of oxygen. The SCR activities of the catalysts with different supports increases in the order of Ce/TiO2 < Ce/TiO2-20SiO2 ≈ Ce/TiO2-3.5Al2O3 < Ce/TiO2-20SiO2-3.5Al2O3. The Ce/TiO2-20SiO2-3.5Al2O3 catalyst showed 100% NO conversion in the temperature range of 250-425°C and 100% N2 selectivity in the whole temperature range. The catalytic activity of Ce/TiO2-20SiO2-3.5Al2O3 exhibited good stability and strong resistance to SO2 and H2O poisoning. The co-introduction of SiO2 and Al2O3 into TiO2 could increase the amount of chemisorbed oxygen and Lewis acid sites on the surface of catalyst, which should be responsible for the excellent SCR activity.

Porous Ni-Mn oxide nanosheets in situ formed on nickel foam as 3D hierarchical monolith de-NO(x) catalysts

In this work, we successfully in situ decorated nickel foam with porous Ni-Mn oxide nanosheets (3DH-NM/NF) as 3D hierarchical monolith de-NOx catalysts via a simple hydrothermal reaction and calcination process. The catalysts were carefully examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, elemental mapping, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction and NH3 temperature-programmed desorption measurements. The results indicated that the nanosheets are composed of a Ni6Mn1O8 spinel and the metal species are uniformly dispersed in bi-metal oxides. As a result, the strong synergistic effects between the Mn and Ni species have been observed. The active oxygen species, reducible species and acidity are enhanced by the in situ formation of the nanosheets on the surface of nickel foam. These desirable features of 3DH-NM/NF catalysts bring about the excellent de-NOx performance. Moreover, the 3DH-NM/NF catalysts also present good stability and H2O resistance. Based on these favorable properties, 3DH-NM/NF could be considered as a promising candidate for the monolith de-NOx catalysts.

Structure and special chemical reactivity of interface-stabilized cerium oxide nanolayers on TiO2(110)

Novel interface-stabilized ceria nanophases have been grown on TiO2(110) by physical vapor deposition. At low coverage, dumbbell nanostructures constituted by reconstructed titania and ceria clusters are formed, while long range ordered nanoxides can be obtained by increasing the ceria dose. Scanning tunneling microscopy and photoemission spectroscopy were used to characterize the electronic properties of the films, showing that the TiO2 substrate can effectively stabilize ceria in reduced form over a wide range of experimental conditions. Epitaxial coupling is a very useful tool for tuning the chemical properties of mixed oxide systems. The special electronic properties of the films have a direct counterpart in the chemical activity, which has been investigated by temperature programmed desorption using methanol as a probe molecule. The experimental results indicate an exceptional activity of the ceria-titania interface in the selective dehydration of methanol to formaldehyde at an unprecedented low temperature (330 K).

Fabrication and properties of lightweight ZrB2 and SiC-modified carbon bonded carbon fiber composites via polymeric precursor infiltration and pyrolysis

The lightweight UHTC-modified CBCF composites were prepared by PIP using B and Zr polymeric precursor. The mechanical properties, thermo properties and oxidation behavior were studied. They are important considerations for potential use in thermal protection system applications.