Synthesis, Characterization, and NH-SCR Catalytic Performance of Fe-Modified MCM-36 Intercalated with Various Pillars.

Two series of MCM-36 zeolites intercalated with various pillars and modified with iron were synthesized, analyzed with respect to their physicochemical properties, and tested as catalysts for the NH-SCR process. It was found that the characteristic MWW morphology of MCM-36 can be obtained successfully using silica, alumina, and iron oxide as pillars. Additionally, one-pot synthesis of the material with iron resulted in the incorporation of monomeric Fe species into the framework positions.

Hydrotalcite-Modified Clinoptilolite as the Catalyst for Selective Catalytic Reduction of NO with Ammonia (NH-SCR).

A series of clinoptilolite-supported catalysts, modified with hydrotalcite-like phase (HT) by co-precipitation, were prepared and tested in NH-SCR reactions. It was found that deposition of HT on clinoptilolite increased conversion of NO within 250-450 °C, and that the positive impact on the catalytic activity was independent of HT loading. The promoting effect of clinoptilolite was attributed to Brönsted acid sites present in the zeolite, which facilitated adsorption and accumulation of ammonia during the catalytic process.

Catalytic Performance and Sulfur Dioxide Resistance of One-Pot Synthesized Fe-MCM-22 in Selective Catalytic Reduction of Nitrogen Oxides with Ammonia (NH-SCR)-The Effect of Iron Content.

The catalytic performance of Fe-catalysts in selective catalytic reduction of nitrogen oxides with ammonia (NH-SCR) strongly depends on the nature of iron sites. Therefore, we aimed to prepare and investigate the catalytic potential of Fe-MCM-22 with various Si/Fe molar ratios in NH-SCR. The samples were prepared by the one-pot synthesis method to provide high dispersion of iron and reduce the number of synthesis steps.

Catalytic Performance of One-Pot Synthesized Fe-MWW Layered Zeolites (MCM-22, MCM-36, and ITQ-2) in Selective Catalytic Reduction of Nitrogen Oxides with Ammonia.

The application of layered zeolites of MWW topology in environmental catalysis has attracted growing attention in recent years; however, only a few studies have explored their performance in selective catalytic reduction with ammonia (NH-SCR). Thus, our work describes, for the first time, the one-pot synthesis of Fe-modified NH-SCR catalysts supported on MCM-22, MCM-36, and ITQ-2. The calculated chemical composition of the materials was Si/Al of 30 and 5 wt.