Complete oxidation of formaldehyde at room temperature over an Al-rich Beta zeolite supported platinum catalyst

Abstract

For human health and environmental protection, removal of formaldehyde (HCHO) has become a hot topic, and completely catalytic oxidation at room temperature has been identified as one of the efficient routes for solving this problem. Recently, it has been reported that zeolite-supported Pt catalysts are active for HCHO oxidation at low temperatures, but they are still unable to completely oxidize HCHO at room temperature. To enhance the activity, it has been suggested to increase the Pt dispersion and acidic density in the zeolite-supported Pt catalysts. We therefore chose Al-rich Beta as a zeolite support because abundant aluminum species in the zeolite framework are advantageous for increasing acidic density through ion-exchange of protons and for improving Pt metal dispersion through the metalzeolite interaction by increasing the negative charge of the zeolite framework with positively charged metal ions. As we expected, the Al-rich Beta zeolite supported platinum catalyst is very active, giving complete oxidation of HCHO at room temperature. To the best of our knowledge, this is the first time the complete oxidation of HCHO at room temperature over a zeolite-supported noble metal catalyst has been realized. In addition to its extraordinary activity, this catalyst is also very stable and selective. The strategy of designing zeolite-supported noble metal catalysts might offer an alternative way to develop highly efficient heterogeneous catalysts for the removal of air pollutants.

Synergism between non-thermal plasma and photocatalysis: Implicationsin the post discharge of ozone at a pilot scale in a catalytic fixed-bed reactor

“…10) during the catalytic oxidation of Butyraldehyde. This observation shows that humidity enhances the decomposition of Ozone on ZSM-5 into hydroxyl radicals and consequently favors mineralization [31][32][33][34]. Indeed, CO2 reached the highest selectivity at the outlet of fixed-bed reactor with a rate of 81.61% against 40.7% for DBD-plasma/photocatalytic reactor and a higher performance in Ozone removal on ZSM-5.…”

Pd/Lewis Acid Synergy in Macroporous Pd@Na‐ZSM‐5 for Enhancing Selective Conversion of Biomass

“…However, most studies focus on the Brønsted acid sites in zeolite catalytic systems, [23–25] and there are rare reports on the design and study of Pd/Lewis acid sites. Generally, Brønsted acid sites are attributed to the framework Al in highly crystallized zeolites, which is commonly obtained by hydrothermal process [26,27] . Therefore, to design Pd/Lewis sites system, we present a direct steam‐thermal crystallization approach to obtain low crystallized Pd/macroporous ZSM‐5 (denoted as Pd@ZSM‐5) with a large amount of extra framework Al.…”

Solvent-free crystallization of ZSM-5 zeolite on SiC foam as a monolith catalyst for biofuel upgrading

“…Zeolite-based catalysts have been extensively used in fuel upgrading, pollutant removal, and fine chemical synthesis, because of their large surface areas, uniform microporous structures, suitable acidity, and rigid frameworks with outstanding thermal stability [1][2][3][4][5][6][7][8][9][10][11]. Generally, zeolite-based catalysts are localized in fixed-bed reactors in the form of powdered microgranules or extrudates, which are extensively used in the current practical processes, but the mass transfer on these catalysts still needs to be improved [12].…”