01919nas a2200229   4500008004100000022001400041245015400055210006900209260009500278300001200373490000800385520100700393653001601400653002501416653001701441653003001458653001801488100002001506700002401526700001701550856012201567       2007                        eng d  a0021-951700aSynergistic role of acid sites in the Ce-enhanced activity of mesoporous Ce-Al-MCM-41 catalysts in alkylation reactions: FTIR and TPD-ammonia studies0 aSynergistic role of acid sites in the Ceenhanced activity of mes  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcJAN  a338-3470 v2453 a<p>The acidic properties of Ce-x-Al-y-MCM-41 with different Ce/Al/Si atomic ratios were examined by pyridine-FTIR and ammonia-TPD methods. Both the density and the strength of the acid sites were considerably higher in the samples containing both Ce and Al than in the samples with only one of these substituents. The IR spectra of chemisorbed pyridine revealed that the Ce-Al-MCM-41 samples contained at least two distinct Lewis acid sites, L-2 (1595-1444 cm(-1)) and L-1 (1613-1452 cm(-1)), where the L-2/L-1 ratio increased progressively with increasing Ce/Al atomic ratio in a series of samples with similar Si/Al ratios. In addition, the density of the Bronsted acid sites (B) as well as the B/L-1 ratio increased with increasing Ce/Al molar ratio in these samples. The findings of this study help us understand the synergistic role played by Lewis and Bronsted acid sites in the catalytic activity of these catalysts for the benzylation of toluene. (c) 2006 Elsevier Inc. All rights reserved.</p>10aammonia-TPD10abenzylation reaction10aCe-Al-MCM-4110aFriedel-Crafts alkylation10apyridine-FrIR1 aKalita, Pranjal1 aGupta, Narendra, M.1 aKumar, Rajiv  uhttps://library.ncl.res.in/content/synergistic-role-acid-sites-ce-enhanced-activity-mesoporous-ce-al-mcm-41-catalysts