Insight into the correlation between the adsorption-transformation behaviors of methylthiophenes and the active sites of zeolites Y

Ultra-deep adsorptive removal of thiophenic sulfur compounds from FCC gasoline over the specific active sites of CeHY zeolite

“…Inconceivably, both the color of HY and CeHY samples become claybank after adsorbed TP or 2-MTP. This phenomenon implys that adsorptive desulfurization mechanism is not just the simply direct "S-M" bonding interaction between the TP or 2-MTP and the active sites of HY and CeHY zeolites, but also it's very likely that the catalysis conversion reactions have been occurred, as reported in the literatures [34,39,52] . When the four thiophenic sulfur compounds are mixed in the n -octane, it also can be seen that the selectivity for the removal of sulfur compounds decreases in the order of THTP > 2-MTP > BTP > TP (cf.…”

“…6 (b-2) and (b-3), lines (3)-(5)), it can obtain a similar conclusion that the adsorbed 2-MTP species can be polymerized, decomposed or cracked under higher desorption temperatures. These processes have been explained in our previous work by IGA-MS technique [52] .…”

“…1454 cm −1 are ascribed to Brønsted acid sites and Lewis acid sites, respectively, and the respective total acid amount is shown in Table 3 . In the present reports, the http://engine.scichina.com/doi/10.1016/j.jechem.2019.04.010 [34,39,52,59] . In particular, the Ce hydroxylated species obviously strengthen acidity and increase density of Si(OH)Al groups located in the supercages of CeHY zeolite (see the band at ca.…”

“…However, a recent literature has found that the protonation and oligomerization reactions of methylthiophenes on the REUSY zeolite can also occur at ambient temperature [52] . In addition, Valla et al have demonstrated that the Ce-exchanged Y zeolite can exhibit multiple adsorption modes, as they can adsorb the benzothiophene via π complexation and σ -bond interaction [29,53] .…”

Insight into the nature and the transformation of the hydroxyl species in the CeY zeolite

“…[10][11][12][13]16,19,28 These diverse hydroxyl species are inclined to be located in the supercages (O(1)H), the six-membered rings shared by sodalite cages and supercages (O(2)H), and the sodalite cages(O(3)H). In our previous studies, 6,8,29,30 we have found that the hydroxyl group distribution of REY zeolite is affected by the RE loadings and calcination temperatures.…”