D.Yogeswara Rao

Bio: D.Yogeswara Rao is an academic researcher. The author has contributed to research in topics: Decomposition & Thermal decomposition. The author has an hindex of 1, co-authored 1 publications receiving 12 citations.

A Review on CO Oxidation Over Copper Chromite Catalyst

Abstract: CO is a toxic and detrimental air pollutant. It not only affects human beings but also vegetation and indirectly increases global warming. An estimate has shown that vehicular exhaust contributes about 64% of the CO pollution in developed countries. Due to the exponentially increasing number of automobiles on roads, CO concentrations have reached an alarming level in urban areas and regulatory measures had been adopted to curb the menace of vehicular pollution. To control vehicular exhaust pollution, end-of-pipe-technology using noble metals catalytic converters are recommended. The increasing prices of noble metals with the increasing number of vehicles motivates the investigation of material concepts to reduce the precious metal content in automotive catalysts or to find a substitute for noble metals. Among non-noble metals, copper chromite is found to be most promising and exhibits comparable activity for CO oxidation to that of precious metals. Further, low cost, easy availability and advance synthesi...

Effect of heat-treatment conditions on CuCrγ-alumina catalyst for carbon monoxide and propene oxidation

Abstract: The activity behavior of carbon monoxide and propene oxidation on Cu Cr catalysts was investigated by varying both the catalyst composition and the heat-treatment conditions. γ-Alumina supported CuO, Cr 2 O 3 and Cu Cr oxide catalysts were employed. The Cu Cr catalysts were treated by heating at 300–900°C under oxidizing or reducing atmosphere. Calcined at 700–900°C under oxidizing atmosphere, the formation of Cu 2 Cr 2 O 4 spinel structure resulted in an enhanced activity not only for carbon monoxide oxidation but also for propene oxidation. On the other hand, treatment in a reducing atmosphere at 700–900°C produced a sintered copper surface but induced a strong metal-support interaction that led to an enhancement in activity, but only for carbon monoxide oxidation. Additionally, the synergistic effect resulting from the ligand effect, as Cr 2 O 3 species is closely associated with CuO species, occurs for carbon monoxide oxidation. The activity of propene oxidation on the CuO catalyst reaches a maximum at a copper content of about 10 wt.-% and that on the Cr 2 O 3 catalyst reaches a maximum at a chromium content of about 25 wt.-%.

The role of copper-chromium oxide catalysts in the thermal decomposition of ammonium perchlorate

Abstract: The catalytic effects of doped or mixed CuO-Cr2O3 oxides on the thermal decomposition of ammonium perchlorate (AP) were investigated by using DTA, electrical conductivity and X-ray diffraction techniques. The results obtained revealed that the decrease in the defect electron of CuO catalyst doped with 1 at.% Cr3+ inhibited its activity, while the opposite effect was observed when Cr2O3 was doped with 1 at.% Cu2+. On increase of the concentrations of both oxides, the catalyst containing 70 at.% Cr3+ was found to be the most active during the decomposition of AP. The existence of CuCr2O4 at this ratio was demonstrated by X-ray diffraction. The activity of this spinel was explained on the basis of a hopping mechanism between Cr3+/Cr4+ active sites. Finally, the activation energies of different decomposition stages of AP alone and mixed with catalysts were calculated.