CO2 adsorption over ion-exchanged zeolite beta with alkali and alkaline earth metal ions

VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS

“…The addition of barium resulted in an increase in the number of basic sites (ca. 2.5-fold), in agreement with results in the literature [Yang and Kim, 2010;Zhang and Singh, 2008], and in a 50% decrease of the surface area of Al-MCM-41 due to the formation of Ba 2 SiO 4 particles that block the entry of the channel structure of the mesoporuos silica. At the beginning of the catalytic tests at 573 K and W/F EtOH = 15 g h mol -1 (Figure 6b), the ethanol conversion was 66% and the selectivity for ethylene was 38% and for diethyl ether 56%.…”

“…In previous studies, it was reported that CO 2 can be absorbed irreversibly on OH -groups (basic sites) producing CO 3 2-and H 2 O species [Cheng et al, 1998]. Therefore, an increase of the catalyst basicity can be assigned to the alkali-earth properties of barium [Yang and Kim, 2010;Zhang and Singh, 2008] and to the tendency to form carbonates on the chromium surfaces [Seiferth et al, 1999;Kuhlenbeck et al, 1992]. Figure 4 shows the IR transmission spectra of samples in the range 4000-400 cm -1…”

Carbon dioxide adsorption over zeolite-like metal organic frameworks (ZMOFs) having a sod topology: Structure and ion-exchange effect

“…As an alternative, adsorptive CO 2 removal processes employing various solid adsorbents such as zeolites [2][3][4][5][6][7][8][9], activated carbons [10][11][12], hydrotalcite [13], and amine-functionalized porous materials [14][15][16][17][18][19] have also been actively pursued. In particular, a new class of porous hybrid materials known as metal organic frameworks (MOFs) has attracted a great deal of interest recently as a potential CO 2 adsorbent and storage material [20][21][22][23][24][25][26][27][28].…”

“…It is worth noting that Nouar et al [37] and Calleja et al [38] studied hydrogen adsorption over several ion-exchanged ZMOF samples and observed a negligible enhancement effect by exchanged ions. However, it is expected that CO 2 would interact more strongly with ion-exchanged ZMOFs via a cation-quadrupole interaction, similar to the case of zeolites; the polarizing power of the exchangeable cations and their distribution, size, and number influence the local electric field and the polarization of the adsorbed molecules on zeolites [8].…”

Polyethylenimine-incorporated zeolite 13X with mesoporosity for post-combustion CO2 capture

“…Zeolites have been widely investigated as a CO 2 adsorbent [6][7][8][9][10][11], especially zeolite 13X, which has been considered to be a benchmark material for CO 2 capture owing to its high CO 2 capture capacity [6][7][8]. However, zeolites are usually utilized as CO 2 adsorbents at low or ambient temperatures due to the thermodynamics of the physical adsorption involved, and low CO 2 capture selectivity toward N 2 is another disadvantage for their application in post-combustion systems.…”