Hydroxyl Groups Promoted Ag Dispersion and Excellent Performance of Ag/Al2O3 Catalyst for HCHO Oxidation

Abstract

Hydroxyl groups are considered as anchoring sites for active components on catalysts. Guided by this viewpoint, 4 wt. % Ag/Al2O3 catalyst derived from Boehmite (AlOOH) was prepared and showed 100% formaldehyde conversion to CO2 at 75 °C. The results of 1H MAS NMR, UV–vis spectra and Transmission electron microscopy (TEM) images suggest that the abundant bridging OH groups are prominently contributed to Ag anchoring and the formation of large content of small sized metallic Ag with high dispersion and Agnδ+ cluster, and thus facilitating the catalytic oxidation of formaldehyde. This work will pave an attractive way for Ag/Al2O3 catalysts design and application. The enrichment of bridging OH groups of AlOOH contributes to high dispersion of Ag particles and the formation of large content of small sized metallic Ag and Agnδ+ cluster, thus facilitating the HCHO catalytic oxidation.