CsxCo/Na-MOR coating on ceramic monoliths for co-adsorption of hydrocarbons mixture and selective catalytic reduction of NOx

SERRA, RAMIRO; GOMEZ, LETICIA; TISCORNIA, INES; DEHARBE, MILAGROS; BOIX, ALICIA

Catalysts

MDPI

Año: 2023 vol. 13 p. 1 - 16

In this work, ceramic monolithswere coated with powders based on exchanged Cs and/or Co cations in Na-mordenite(MOR) zeolite. SEM images showed that zeolite particles fill the macropores ofcordierite walls and form a continuous layer of approximately 40 µm with goodadherence. XPS analysis revealed that Co and Cs are present on the film surfacesolely as Co2+ and Cs+ at exchange positions in zeolite.The monolithic structures were evaluated for the butane-toluene co-adsorptionand SCR of NOx with hydrocarbon mixture as reducing agent. The presence ofalkali metal cations in the zeolitic lattice favored the adsorption capacity ofboth hydrocarbons, while cobalt cations provoked a decrease of adsorbed amountsdue to its weak interaction with the HCs. Breakthrough curves of butaneadsorption showed roll-up phenomenon, associated to competitive adsorptioneffect generated from toluene presence. In desorption process, it was observedthat adsorbed toluene hindered the butane diffusion through mordenite channels,which released at higher temperature (above 250 °C). Cs2CoM and Cs7CoMmonoliths were more active than CoM monolith for NO-SCR. The presence of Cscations close to Co cations increased the hydrocarbons concentration aroundactive sites at high temperature, according to TPD results, promoting thereduction activity of NO.