CsxCo/Na-MOR Coating on Ceramic Monoliths for 2 Co-Adsorption of Hydrocarbons Mixture and Selective 3 Catalytic Reduction of NOx

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

catalysts

MDPI JOURNAL

Año: 2022

2073-4344

In this work, ceramic monoliths were coated with powders based on exchanged Cs and/or Co cations in Na-mordenite (MOR) zeolite. SEM images showed that zeolite particles fill themacropores of cordierite walls and form a continuous layer of approximately 40 µm with good adherence. XPS analysis revealed that Co and Cs are present on the film surface solely as Co2+ and Cs+ at exchange positions in zeolite. The monolithic structures were evaluated for the butane-toluene co-adsorption and SCR of NOx with hydrocarbon mixture as reducing agent. The presence of alkali metal cations in the zeolitic lattice favored the adsorption capacity of both hydrocarbons, while co- balt cations provoked a decrease of adsorbed amounts due to its weak interaction with the HCs. Breakthrough curves of butane adsorption showed roll-up phenomenon, associated to competitiveadsorption effect generated from toluene presence. In desorption process, it was observed that adsorbed toluene hindered the butane diffusion through mordenite channels, which released at higher temperature (above 250 °C). Cs2CoM and Cs7CoM monoliths were more active than CoM monolith for NO-SCR. The presence of Cs cations close to Co cations increased the hydrocarbons concentra- tion around active sites at high temperature, according to TPD results, promoting the reduction 22activity of NO.