Study On Selectively Reducing Carbon Monoxide Of Cigarette Smoke

It is a challenge to reduce the amount of carbon monoxide and harmful components in the cigarette and at the same time ensure the smoker in a physical contentment. Inexpensive metal oxide catalyst, due to its low temperature high active adsorbed oxygen and high temperature high active lattic oxygen and other superior characteristics, such as catalytic activity as high as the expensive one, raw material cheap and easy to obtain, high thermal stability, has drawn more and more people's attention.In this paper according to the low temperature catalytic mechanism, the inexpensive metal catalyst material which is suitable for the cigarette industry was manufactured and applied in the cigarette filter to test its ability to lower the amount of carbon monoxide in the cigarette smoke. The study focused on several parameters:1) Based on the study of carbon monoxide in the cigarette smoke, the impact of catalyst active components, preparation method, active component atom ratio and baking temperature was studied specifically, the optimal preparing condition was determined: precipitation oxidation reaction method prepared Co3O4/CeO2exhibits the highest reducing effect of carbon monoxide when the ratio of Co:Ce equals to 9:1, the reaction temperature reaches to 50 or 60℃, baking temperature is set to 265℃, baking time lasts for 4 hours, pH was adjusted from 8 to 11, Na2CO3 as the precipitant and azeotropic distillation is applied. Comparing with the control cigarette, the decreasing rate of CO is up to 7.56%. Duplicate test shows good reproducibility and stability. The reducing rate ranges from 6% to 7%.2) Segmented addition as the most appropriate addition technique is determined. The amount of catalyst affecting the effect of reducing CO was studied; it shows that the moisture and repeat use of the catalyst lower the catalytic activity. Drying treatment of the catalyst no less than 300℃, the catalytic activity and selectivity could recover.3) The crystal phase structure, specific surface area and redox characteristic were tested by using XRD, BET and TPR testing method, respectively, which shows Co3O4/CeO2 is characterized by small particle size, large surface area and good dispersibility and is preferred catalyst.4) The mechanism of reducing CO in the cigarette smoke lies in two aspects:one is adsorption catching of the complex oxide catalyst; another is the complex oxide catalyst resembling in meso-porous solid, which can catalyze the CO into CO2 at a low temperature.