Catalytic performance of pillared interlayered clays (PILCs) supported CrCe catalysts for deep oxidation of nitrogen-containing VOCs

Na-montmorillonite (Na-mmt) and different pillared interlayered clays (Al-PILC, Zr-PILC, Ti-PILC and Al2O3/Ti-PILC) supported CrCe catalysts for the deep oxidation of nitrogen-containing VOCs (NVOCs) are synthesized and characterized by a combination of X-ray diffraction, N2 adsorption/desorption, high resolution transmission electron microscopy, temperature-programmed reduction, temperature-programmed desorption and adsorption capacity tests techniques. The results indicate that a porous structure named “house of cards” forms during the pillaring and calcination processes. Both porous structure and acidity play important roles in deep oxidation of NVOCs. The mesoporous structure and the proper acid sites improve the catalytic activity of supported CrCe catalysts. Among all these catalysts, CrCe/Ti-PILC and CrCe/Al2O3/Ti-PILC exhibit higher catalytic activity than other catalysts. N-butylamine and ethylenediamine with –NH2 groups are easier to be destructed may be involved in the stronger adsorption on the acid sites of the catalysts. Much too strong adsorption of ethylenediamine on the acid sites leads to a lower activity compared with n-butylamine. Acetonitrile with C≡N bond and little interaction with acid sites is the most difficult to be decomposed. All the catalysts show a good control quality of NOx, and the yield of NOx is limited within 2% during the whole experimental temperature range.