Lithium promotes Ag-CoOx composite for formaldehyde oxidation at ambient temperature: Chemically adsorbed oxidative oxygen formed by the interaction between AgCoO2 and catalyst parent

Catalytic oxidation at ambient temperature dominates priority in airborne formaldehyde elimination. Herein, the effects of Li+, Na+ and K+ on the catalytic activity of Ag-CoOx composite were comparatively studied. Systematic methods were applied to investigate the factors influencing catalytic activity. Compared with the cases of Na+ and K+, for which the combination with Ag species respectively deteriorated and limitedly increased formal-dehyde removal, the incorporation of Li+ greatly boosted formaldehyde degradation. Characterization results certify that the largest amount of chemically adsorbed active oxygen was crucial to the excellent performance of Li-Ag-CoOx, and the advanced oxidizing property can be rationalized by the strong interaction between the exclusively formed AgCoO2 and the catalyst parent. This is the first time to clarify the roles of varied alkaline metals in the complete oxidation of formaldehyde catalyzed by Ag-CoOx materials. Effects of process variables were additionally investigated to uncover the catalyst suitability for in-field application.