Deep oxidation of gaseous formaldehyde at room-temperature by a durable catalyst formed through the controlled addition of potassium to platinum supported on waste eggshell

Abstract

Catalytic oxidation of pollutant(s) into innocuous end products (carbon dioxide (CO2) and water) without heat or light sources is an ideal option for air quality management. In pursuit of such goal, platinum (Pt) supported by waste eggshell (biogenic calcium carbonate), namely Pt/eggshell, is synthesized through a simple wetness impregnation approach to catalyze 100 ppm formaldehyde (FA) into CO2 at room temperature (RT: 30 °C). The co-impregnation of potassium (K) alongside Pt leads to a full-sclae (100%) enhancement in the net catalytic activity to destruct FA. The in-situ diffuse reflectance infrared Fourier transform spectroscopy analysis suggests the FA oxidation pathway to involve dioxymethylene, formate, and carbon monoxide intermediates. The FA reaction pathways and associated mechanisms are also accounted for based on the density functional theory simulations. This study opens a new path for developing high-performance biowaste-derived catalysts for the complete mineralization of gaseous FA without the supply of external energy sources.