Balu S. Uphade

Low-Temperature Selective Catalytic Reduction (SCR) of NO with NH3 by Using Mn, Cr, and Cu Oxides Supported on Hombikat TiO2

A Highly active, time stable, and water resistant, Hombikat TiO2 supported Mn catalyst has been developed for the selective reduction of NO by NH3 [Eq. (1)]. The analogous Cu and Cr supported catalysts also provide 100 % N2 selectivity at ≤120°C. Lewis acidity, redox properties, and a high surface metal oxide concentration are essential for good catalytic performance.

Simultaneous steam and CO2 reforming of methane to syngas over NiO/MgO/SA-5205 in presence and absence of oxygen

Abstract Steam reforming, CO 2 reforming and simultaneous steam and CO 2 reforming reactions of methane for its conversion into syngas (H 2 and CO) over NiO/MgO/SA-5205 catalyst (prepared by depositing NiO on MgO precoated SA-5205 support) have been investigated at different process conditions. In some cases O 2 was present in the feed, while in other cases it was not. The catalyst has been characterised by its temperature programmed reduction and also, after its reduction, by temperature programmed desorption of hydrogen. It showed high activity and selectivity in the above methane-to-syngas conversion reactions at low contact times. The H 2 /CO product ratio in the simultaneous methane conversion reactions showed a strong dependence on the feed composition; such dependence is increased by increasing the concentration of steam relative to that of O 2 and/or CO 2 in the feed. In the oxy-steam and/or CO 2 reforming reactions, there is a direct coupling of the exothermic and endothermic reactions and hence these processes over the catalyst occur in the most energy efficient and safe manners, requiring little or no external energy. The net heat of reactions in these processes is strongly influenced by the reaction temperature and/or CH 4 /O 2 ratio in the feed. In the simultaneous steam and CO 2 reforming of methane in both the presence and absence of O 2 , it is possible to convert methane into syngas with high conversion (above 97%) and 100% selectivity for both CO and H 2 .

Calcium oxide supported gold nanoparticles as catalysts for the selective epoxidation of styrene by t-butyl hydroperoxide.

Gold nanoparticles are deposited on basic CaO supports as catalysts for the selective conversion of styrene into styrene oxide. Synthetic methods, gold loading and calcination temperatures are varied to permit an understanding of their influence on gold nanoparticle size, the presence of cationic gold species and the nature of interaction between the gold nanoparticles and the CaO support. Based on these studies, optimal conditions are designed to make the Au/CaO catalyst efficient for the selective epoxidation of styrene.

Influence of support on surface basicity and catalytic activity in oxidative coupling of methane of Li-MgO deposited on different commercial catalyst carriers

Deposition of Li-MgO catalyst on commonly used supports (containing SiO 2 , Al 2 O 3 , SiC, ZrO 2 , HfO 2 , etc.) causes a drastic reduction in the catalytic activity/selectivity for the oxidative methane coupling reaction and also in both the total and strong surface basicity. The decrease in the catalytic activity/selectivity and basicity is attributed to strong chemical interactions between the catalyst and support which occur during the high temperature (750°C) calcination/pretreatment of the catalyst. The chemical interactions result in catalytically less active binary and ternary metal oxides containing Li and/or Mg, thus deactivating the Li-MgO catalyst by consuming its active components.