Mineral acid-activated sugarcane bagasse ash as solid acid catalyst for the liquid phase esterification of acetic acid with n-amyl, benzyl, and n-butyl alcohols

Modified natural kaolin clay as an active, selective, and stable catalyst for methanol dehydration to dimethyl ether

“…The FTIR signals located at 1423, 1458, and 1490 cm −1 corresponded to pyridine coordinated at (L) sites. The signals that arose at 1507, 1542, 1637, and 1650 cm −1 were related to pyridine molecules protonated at (B) sites 58 , 59 . The FTIR spectrum of the K400 sample pre-saturated with pyridine exhibited two signals centered at 1423 and 1637 cm −1 , which can be attributed to the (L) and (B) acid sites bound to pyridine, respectively.…”

“…Isopropyl alcohol (IPA) was dehydrated as previously described by Said et al 11 , and the pyridine FTIR (Py-FTIR) adsorption technique were used 59 . Those were done to measure the acidity of the catalysts.…”

Zirconia–sugarcane bagasse fly ash as a novel solid acid nanocatalyst for selective dehydration of methanol to dimethyl ether

“…It contains high amounts of SiO 2 (~75.6%) and low amounts of other metal oxides. The (SiO 2 + Al 2 O 3 + Fe 2 O 3 ) content is ~79.6%, reflecting that the SCBFA used belongs to a class F fly ash according to ASTM C 618 [7]. Oxides of other elements such as Ca, Mg, Na, K, Mn, and Ti were also detected in the XRF analysis.…”

“…Figure 2a shows the FTIR spectra of SCBFA, 1–20% ZrO 2 /SCBFA, and 1–10% SO 4 2− /20% ZrO 2 /SCBFA catalysts calcined at 400°C. Raw SCBFA showed absorption bands that can be ascribed as follows: 3432 cm −1 (surface –OH groups of the Si–OH and adsorbed H 2 O molecules on the surface), 1630.5 cm −1 (bending mode (δO–H) of the H 2 O molecule), 1096 cm −1 (valence oscillation of Si–O–Si groups), 796 cm −1 (symmetric stretching mode of the Si–O–Si vibrations), and 464 cm −1 (bending frequency of O–Si–O) [7]. The broadness of the band at 3432 cm −1 indicated the strong hydrogen bonding [4].…”

Highly selective esterification of bioderived itaconic acid to monobutyl itaconate: kinetic analysis of a reusable 20% (w/w) Rb0.5Cs2.0H0.5PW12O40/MCF catalyst system

“…Several solid acid catalysts have been studied in recent years for efficient esterification reactions, which include sulfonic-acid-functionalized copolymer poly(F-STs- co -ST), 7 sulfonated magnetic nano biochar, 8 hierarchical mesoporous ZSM-5 containing sulfonic acid groups, 9 capsules loaded with amorphous carbon-based solid acid catalysts, 10 sugarcane bagasse ash treated with sulfuric acid or perchloric acid, 11 activated carbon derived from sunflower shells modified with sulfonic acid groups, 12 sulfonated hyper crosslinked exchange resin, 13 carbon catalysts with a porous structure and sulfonic acid groups, 14 a magnetically recyclable Brønsted acid catalyst prepared by grafting acidic ionic liquids onto magnetic silica composite, 15 solid acid catalysts prepared using zirconium and titanium through the pillarization method, 16 a bamboo charcoal-based solid acid catalyst produced through carbonization and sulfonation with sulfuric acid at low temperature, 17 immobilized polymeric acidic ionic liquid on a magnetic Fe 3 O 4 /SiO 2 composite, 18 core–shell Pd@UiO-66(Hf) MOF 19 and the UDCaT series of catalysts developed in our laboratory. 20,21 These solid acid catalysts exhibit high activity and efficient separation performance, rendering them effective and reusable for esterification reactions among other acid-catalysed organic transformations.…”