Catalytic combustion of toluene on Pd/Ce x La1−x O2/monolith catalysts

Abstract

The heterogeneous catalytic oxidation of volatile organic compounds on Pd/Ce x La 1-x O 2 /monolith catalysts in the temperature range 160-230°C has been studied, which took toluene combustion as a probe reaction. SEM, ICP-OES, XRD, laser Raman spectra, and temperature-programmed reduction (TPR) are used to characterize the Pd/Ce x La 1-x O 2 /monolith catalysts. A high activity of the catalyst with respect to the complete oxidation of toluene to carbon dioxide has been observed. The conversion of toluene approaches 100% at about 210°C.

A computational study on the reaction mechanism of neutral phenol with formaldehyde in aqueous solution

“…It was found that solvent water molecules can also catalyse the process of proton transfer and significantly reduce the reaction energy barrier. Similar results were also obtained for the melamine-formaldehyde reaction [13]. Phenol-formaldehyde (PF) resin is the earliest industrialised synthetic polymer material [14][15][16].…”

“…The results obtained can be compared with those previously reported for other nucleophiles. Different from urea and melamine [13], the nucleophilic centre of phenol is a carbon atom and it is not clear that the reaction between phenol and formaldehyde occurs in a concerted or stepwise mechanism (reaction (4) in Scheme 1). In addition, the polarity of the C-H bond is much weaker than that of the N-H bond in NH 3 , RCH 2 and urea.…”

Catalytic combustion of methane over Pd/Ce–Zr oxides washcoated monolithic catalysts under oxygen lean conditions

“…Pure CeO 2 exhibits two reduction peaks: the rst peak centered at around 500 C corresponds to the reduction of the uppermost layers of Ce 4+ ; the second peak centered on 800 C originates from the reduction of the bulk CeO 2 . 24 The broad reduction peak of CeO 2 and Ce1Zr2 in the temperature range 450-700 C corresponds to the reduction of surface Ce 4+ , while the reduction temperature for bulk CeO 2 is above 800 C. With further addition of Zr, two dominant reduction peaks instead of one for surface reduction were found. The reduction peaks shied to lower temperature thus the oxides are much easier to be reduced.…”

Volatile organic compound removal over bentonite-supported Pt, Mn and Pt/Mn monolithic catalysts

“…Morales et al [34] obtained a T 90 of 210 and 300°C for ethanol and toluene, respectively, over MnCu supported on 330 cpi cylindrical Fecralloy monoliths working at a GHSV of 3,000 h -1 . Li et al [49] studied the combustion of toluene over 0.2 %Pd-6 %Ce x La 1-x O 2 supported on 200 cpi cordierite monoliths (48 9 24 9 40 mm 3 ) working at 0.3 m 3 h -1 , obtained 90 % toluene conversion at 230°C. Monoliths prepared in this work are easy to obtain and are ready made to incorporate the active phase directly by wet impregnation.…”