Modification of the Acidic Properties of NaY Zeolite by H2S Adsorption—An Infrared Study

Zeolite and Metal Oxide Catalysts for the Production of Dimethyl Sulfide and Methanethiol

“…At lesser acid strengths, the increased binding energy of the methyl groups increases the barrier height. This finding is confirmed experimentally in that more acidic oxide catalysts than used here (e.g., PO 4 3-/SiO 2 , silica-aluminas, Nb 2 O 5 ÁnH 2 O), and more basic oxide catalysts than used here (MgO, Na-Y, Cs/Al 2 O 3 , K/Al 2 O 3 ) are in both cases far less active for the sulfidation of methanol [2,7,8,11,20,21]. It is also reflected in the finding that chemisorbed methanol is most reactive on catalysts that are neither strongly basic nor strongly acidic, such as alumina and La 2 O 3 /Al 2 O 3 .…”

“…The solid curves represent calculated values (at 370°C) of methanol conversion, and DME, DMS and MT yields, that result from allowing reactions (3) and (4) to come to equilibrium while holding the extents of reactions (1) and (2) constant. In other words, the total sulfur product yield is held constant, while DMS, MT and DME are allowed to equilibrate according to reactions (3) and (4). For the sulfur product yields observed here, the equilibrium curves do not vary significantly with temperature over the range 340-400°C, so an average temperature of 370°C was used to construct the figure.…”

“…Under all conditions investigated, the affinity for reaction to DME was close to equilibrium (-1 \ A \ 0). The affinity for reaction (4) was negative, indicating that this reaction produces MT from DMS near the reactor exit. Nonetheless, the DMS yield increased with methanol conversion while the MT yield remained relatively constant.…”

“…Further activation can occur by dissociative adsorption (especially for MeOH, MT, H 2 S) on pairs of Lewis acid and base sites [3][4][5][6].…”

Prediction of Three Component Gas Adsorption With Iast and Langmuir

“…It can be verified that H 2 S presents a greater affinity for NaY zeolite than CO 2 or CH 4 . This is due to its strong interaction with zeolite behavior, characterized by three different adsorption behavior (Maugé et al, 2002).…”