Surface characterization and catalytic activity of sulfated tin oxide catalyst

Synthesis of Waste Cooking Oil Based Biodiesel via Ferric-Manganese Promoted Molybdenum Oxide / Zirconia Nanoparticle Solid acid Catalyst: Influence of Ferric and Manganese Dopants

“…The addition of Molybdenum oxide has been related to the size reduction which changes from 25.5 to 10.0 nm for zirconia Z and Fe-Mn-MoO 3 /ZrO 2 FMMZ , respectively. This may be coupled with the Molybdenum oxide which stays bounded to the catalyst surface thus reduce the enlargement of zirconia particles in agreement therefore with the oxides of transition metals, such as titania and stannia 23 . Reduction in the size of crystallite could be illustrated with concept Generally, the strength and the density of energetic centres have been determined via temperature programmed desorption TPD technique.…”

Heterogeneous Tin Catalysts Applied to the Esterification and Transesterification Reactions

“…(iii) an increase in the calcinations temperature of 440 to 550 ∘ C also increases the acidic sites strength, which again was not observed at the temperature of 750 ∘ C [29].…”

“…(ii) in addition, this same increase in the sulfate ions load resulted in the increase of the strength of acid sites, comprised by increase verified in the potential measurements; on the other hand, once more these effects were not observed at the highest temperature [29];…”

“…On the other hand, via the FT-IR analysis of pyridine adsorption, it becomes possible to identify the Lewis and Brønsted acid sites. The acid properties of SO 4 −2 /SnO 2 catalysts synthesized at 400, 550, and 750 ∘ C were reported by Khder and coworkers and are displayed in Table 6 [29]. Table 6 reveals a notable effect provoked by both increase in the sulfate content and increase in the calcination temperature; these main effects are summarized as follows: (i) an increase in the sulfate ions load resulted in the increase of the NAS (number of acid sites); nevertheless, this effect was noticed only in the temperature range of 400 to 550 ∘ C; at higher temperature (i.e., 750 ∘ C), a remarkable reduction in the sites of acid concentration (NAS) occurred, attributed by the authors to decomposition of these sulfate anions [29];…”

“…Khder and coworkers published a study where the effects of sulfate content and calcinations temperature on acidity, structure, and catalytic activity of sulfated tin oxides were assessed [29]. The model reaction selected was acetic acid esterification with amyl alcohol in the vapor phase (ca.…”