The mechanisms of CO formation and reduction under smoldering conditions
Carbon monoxide is a product of tobacco pyrolysis and combustion which occur in a burning cigarette. Previous studies have characterized the major formation pathways of carbon monoxide as the pyrolysis of tobacco, combustion of tobacco char and reduction of carbon dioxide by the tobacco char. A variety of empirical approaches ranging from physical changes in the vicinity of formation to application of numerous inorganic materials and catalysts have been used to reduce the delivery of carbon monoxide from a burning cigarette. In this paper, we provide an overview of the work that was conducted to understand the formation mechanisms of CO and followed by a thorough analysis of the approaches and methodologies that have been used to reduce CO. At the end, we provide new experimental data and theoretical analysis to the continuing challenge of CO reduction in a burning cigarette.