Effects of the nature of the aluminum source on the acidic properties of some mesostructured materials

Transesterification of dimethyl carbonate with diethyl carbonate over Al-Zn-MCM-41 and Al-MCM-41 molecular sieves

“…But these peaks are observed for Al-MCM-41 (50), which contains more aluminum than Al-MCM-41 (100), AlZn-MCM-41 (100) and Al-Zn-MCM-41 (50). These data coincide with those reported earlier [21].…”

Vapour phase esterification of butyric acid with 1-pentanol over Al-MCM-41 mesoporous molecular sieves

“…The XRD powder diffraction patterns of the as-synthesized and calcined materials are shown in the figure1 and they are well matched with those reported earlier [19][20][21][22]. The d 100 values are given in table 1 along with the corresponding unit cell parameter (a 0 ) of the catalysts calculated from the peak with hkl = 100 using the equation a 0 = 2d 100 /Ö3.…”

Catalytic application of Al-MCM-41 in the esterification of acetic acid with various alcohols

“…Weight loss from 120 to 350 8C is due to organic template. The oxidative desorption of the organic template takes place at 180 8C; the minute quantity of weight loss above 350 to 550 8C is related to water loss from the condensation of adjacent Si-OH groups to form siloxane bonds [22]. It is seen that, as the Al content in MCM-41 framework increases, the amount of water desorbed increases and the organic species decrease, which confirms the decrease in the hydrophobic character of the catalyst with increasing Al content.…”