Co and Cu-Based Mixed Metal Oxides Foster Reduction of CO and Hydrocarbons Emissions from Small Combustion Devices

Abstract

Residential stoves, commonly used for heating, are a significant source of emissions due to the harmful substances produced during biomass combustion, yet they remain largely unregulated. The use of catalytic systems presents a promising approach for mitigating these emissions. This study investigates the potential of Cu–Mg–Mn–Al and Co–Mg–Mn–Al mixed metal oxides, synthesized from hydrotalcite precursors via coprecipitation and calcination, for reducing emissions of CO, C₃H₈, and CH₄. The physicochemical properties of the catalysts were thoroughly characterized using techniques such as AAS, XPS, XRD, H₂-TPR, CO₂-TPD, and NH₃-TPD. Catalytic performance was evaluated over a temperature range of 100–500 °C in both two-component (CO + C₃H₈ or CO + CH₄) and three-component (CO + C₃H₈ + CH₄) gas mixtures with oxygen. Results revealed that Co-based catalysts outperformed Cu-based ones in catalytic activity. However, in the three-component mixture, catalytic activity decreased, likely due to competitive adsorption and interactions with active oxygen species. These preliminary findings underscore the potential of mixed metal oxides for emission control in residential stoves, setting the stage for further optimization and application.