Sulfated Alumina Catalysts: Consequences of Sulfate Content and Source

The catalytic decomposition of CF4 over Ce/Al2O3 modified by a cerium sulfate precursor

“…In fact, sulfate ions are incapable of changing the bulk structure of ␥-alumina. The sulfate ions are likely present as dispersed surface species rather than clusters or multilayers [25]. Although we could not detect the sulfate phase by XRD, elemental analysis (EA) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) were able to detect sulfur.…”

“…Thus, CAS and AS begin to react at the relatively low temperature of 500 • C. As CAS has higher activity than the AS, it seems that alumina has a synergistic effect with rare earth element, cerium, via a precursor in the CF 4 hydrolytic decomposition. Notably, sulfated metal oxides have attracted the attention of many researchers over the last few years due to their high activity in reactions for which acid catalysis plays a key role [25,26]. Therefore, the focus of this study was the doping effect of sulfate in CAS, which was prepared by cerium sulfate, AS, which was sulfated.…”

Synthesis of waste cooking oil-based biodiesel via effectual recyclable bi-functional Fe2O3MnOSO42−/ZrO2 nanoparticle solid catalyst

“…From these spectra, the presence of the sulfate group was confirmed by the band at a range of 1225 to 1070 (cm À1 ), which was attributed to the symmetric stretching of the OASAO bond and the asymmetric stretching frequency of the O@S@O bond, respectively. The peak around 1380 cm À1 was attributed to the sulfate groups having an S@O bond with a covalent character [36,37].…”

Esterification of Glycerol with Acetic Acid over Highly Active and Stable Alumina-based Catalysts: A Reaction Kinetics Study

“…This shift is mostly due to the formation of new sulphate species in case of such sulphate loading. 34 …”