Search

A significant enhancement of the yttrium-stabilized zirconia-supported palladium (0.2 wt % Pd/YSZ) catalytic activity for the total oxidation of methane was achieved in a dual-bed system by the association of LaMnO3+Pd/YSZ materials. The combination with the best performance was 40 wt % LaMnO3+60 wt % Pd/YSZ. Pd/YSZ and LaMnO3 perovskite were characterized by using the 18O2 exchange technique. A Mars-van Krevelen mechanism was demonstrated over Pd/YSZ at 425 °C. Additionally, it was evidenced that LaMnO3 activated the O2 molecule on the YSZ oxygen vacancy sites to result in a significant increase of the oxidation rate characterized by a correlating decrease of the light-off temperature of 65 °C. [ABSTRACT FROM AUTHOR]

On the basis of the idea of combining high selective catalytic reduction (SCR) activity, high N2 selectivity, and broad operating temperature window, we developed a combined catalyst process that was found to be a convenient way to design a highly efficient SCR process for NO with NH3. The single catalysts of MnO x-CeO2/TiO2 and V2O5-WO3/TiO2 as well as combined catalysts with different configurations were fully characterized by XRD, temperature-programmed reduction of H2, and temperature-programmed desorption of NO/O2. In addition, they were tested for the oxidation of NO or NH3 as well as the SCR of NO with NH3. The correlations between combining configurations and SCR activity results were also revealed. Furthermore, fundamental evidences were given for the rational design of the process and its efficiency maximization (assembly order and catalytic bed volume). An adequate configuration, with MnO x-CeO2/TiO2 and V2O5-WO3/TiO2 active materials, ensures an excellent SCR performance (NO conversion >85 %, N2 yield >70 %, and decreased N2O production) over a wide operating temperature window (from 150 to 400 °C). [ABSTRACT FROM AUTHOR]

Shape-controlled iron oxide nanocrystals were prepared by using an ionic liquid-mediated hydrothermal process. Different morphologies can be synthesised, such as cubes and porous nanotubes. Owing to the different morphologies developed, accessible surface area varies from a few m2 g−1 to more than 50 m2 g−1. These differences result in different oxygen mobilities, and the porous nanorods demonstrate the highest bulk oxygen mobility. Thus, all these shaped materials demonstrate higher activity for the oxidation reaction compared to the commercial reference. In addition, the favourable physical properties, that is high surface area, enable the easy dispersion of noble metal nanoparticles (platinum, palladium and gold); some of these high-surface area noble metal-containing materials demonstrate remarkable catalytic activities. Porous nanorod-supported gold nanoparticles enable the conversion of CO below 100 °C, which is far better than on commercial α-Fe2O3-supported gold for which dispersion of gold remains difficult owing to the low surface area of the commercial support. [ABSTRACT FROM AUTHOR]

Cover all your bases The cover image shows the principle of catalyst combination for an ideal autoexhaust control that covers a broad temperature range. In their Full Paper on p.   2263   ff., R. Zhang, S. Royer and co ‐ workers describe a remarkable catalyst combination, of MnCeTi and VWTi active materials, that operates over a broad operating temperature window (from 150 to 400 °C). FundamENtal evidENce is givEN for the rational design of the process and its efficiENcy maximization resulting in an excellENt selective catalytic reduction performance. [ABSTRACT FROM AUTHOR]

The Front Cover shows the oxidation of methane on lanthanum manganate and yttrium‐stabilized zirconia‐supported Pd dual‐bed catalyst system. In their Full Paper, Richard et al. focus on the association of manganese perovskite (LaMnO3) and yttrium‐stabilized zirconia (YSZ) materials for total methane oxidation. A significant enhancement of methane abatement activity is achieved over low loading palladium (0.2 wt. % Pd) supported YSZ catalyst in a promising LaMnO3+YSZ dual bed system, resulting in a significant increase of the oxidation rate with a correlative decrease of the light‐off temperature of 65 °C. It is concluded that LaMnO3 upstream activates the triple ground‐state of molecular oxygen into a low‐lying singlet state improving the oxygen activation on the lacunary YSZ surface. Additionally, a Mars‐Van‐Krevelen mechanism was demonstrated at 425 °C using labeled 18O2 exchange technical. More information can be found in the Full Paper by Richard et al. on page 1921 in Issue 11, 2016 (DOI: 10.1002/cctc.201501398). [ABSTRACT FROM AUTHOR]

The front cover artwork for issue 08/2014 is a collaboration between Beijing University of Chemical Technology (P.R. China) and Poitiers University (France). The image shows the principle on catalyst combination for an ideal autoexhaust control covering a broad temperature range. See the Full Paper itself at . [ABSTRACT FROM AUTHOR]

On the basis of the idea of combining high selective catalytic reduction (SCR) activity, high N2 selectivity, and broad operating temperature window, we developed a combined catalyst process that was found to be a convenient way to design a highly efficient SCR process for NO with NH3. The single catalysts of MnO x-CeO2/TiO2 and V2O5-WO3/TiO2 as well as combined catalysts with different configurations were fully characterized by XRD, temperature-programmed reduction of H2, and temperature-programmed desorption of NO/O2. In addition, they were tested for the oxidation of NO or NH3 as well as the SCR of NO with NH3. The correlations between combining configurations and SCR activity results were also revealed. Furthermore, fundamental evidences were given for the rational design of the process and its efficiency maximization (assembly order and catalytic bed volume). An adequate configuration, with MnO x-CeO2/TiO2 and V2O5-WO3/TiO2 active materials, ensures an excellent SCR performance (NO conversion >85 %, N2 yield >70 %, and decreased N2O production) over a wide operating temperature window (from 150 to 400 °C). [ABSTRACT FROM AUTHOR]

The front cover artwork for issue 08/2014 is a collaboration between Beijing University of Chemical Technology (P.R. China) and Poitiers University (France). The image shows the principle on catalyst combination for an ideal autoexhaust control covering a broad temperature range. See the Full Paper itself at . [ABSTRACT FROM AUTHOR]