Adsorption of Formaldehyde by Wood Enhances the Low-Temperature Formaldehyde Oxidation Performance of Pt/TiO2.

This study investigates the influence of wood's ability to adsorb formaldehyde (HCHO) on the low-temperature HCHO oxidation performance of catalysts. Four types of wood powders from typical tree species (i.e., cypress, bamboo, pine, and metasequoia) and a classic catalyst (i.e., Pt/TiO2) were selected as research subjects and were physically mixed to evaluate their catalytic performance. The results indicate that only pine significantly enhances the low-temperature HCHO oxidation performance of Pt/TiO2. When the mixing ratio is set to 1:1, it exhibits optimal catalytic activity, with the HCHO conversion rate increasing from 15 to 40% at room temperature. Structural characterization reveals that various structural parameters of Pt/TiO2 remained unchanged upon mixing with pine powder. The reaction mechanistic studies indicate that the reaction pathway for low-temperature HCHO oxidation remains consistent in Pt/TiO2-Pine compared to those of Pt/TiO2. Kinetic analysis demonstrates that while incorporating pine does not alter the activation energy, it results in an increase in its pre-exponential factor by several times. Adsorption experiments confirm the excellent HCHO adsorption capabilities of pine powder. Structure-performance relationship analyses indicate that a low concentration of HCHO is readily captured by pine powder and subsequently transferred to adjacent Pt/TiO2 for catalyzing its oxidation into CO2 and H2O, thereby exhibiting commendable performance in room-temperature oxidation. The superior HCHO adsorption capacity of pine powder endows Pt/TiO2 with an enhanced low-temperature HCHO oxidation performance. The present findings provide new insights into potential applications for catalysts as well as efficient technologies for removing HCHO.