Catalysis Today, Vol.339, 174-180, 2020
Exceptional activity for formaldehyde combustion using siliceous Beta zeolite as a catalyst support
There is a critical need for improving catalyst activity for formaldehyde combustion due to the importance of enhancing the quality of indoor air in daily life. However, the current catalysts are either low activity (higher than room temperature) or high loading of noble metals (higher than 1 wt.% Pt). Herein, inspired by the concept of catalyst wettability, we design a siliceous Beta zeolite with more hydrophobic feature than that of aluminosilicate Beta zeolite to support Pt catalyst at very low loading (0.2 wt.%), exhibiting extremely excellent catalytic performance in formaldehyde combustion. The formaldehyde could be completely oxidized to carbon dioxide even at -20 degrees C. The extraordinary catalytic properties are reasonably attributed to that more hydrophobicity of the siliceous zeolite than that of the aluminosilicate zeolite is favorable for desorption of water product, shifting the oxidation equilibrium from HCOOH (intermediate of oxidation of formaldehyde) to carbon dioxide and water. The strategy of hydrophobic zeolite-supported noble metal catalysts might offer an alternative way to develop highly efficient heterogeneous catalysts for the removal of volatile organic compounds.