Performance of Catalytic Reduction of Cr(VI)by Bamboo-based Porous Carbon Based on CO2 Activation
Bamboo-based porous carbon(ZH-100)used for the catalytic reduction of Cr(VI)was prepared from bamboo powder and CO2 as an activator.The effects of reaction temperature,catalyst dosage of formic acid,reducing agent dosage,and initial mass concentration of Cr(VI)and other factors on the catalytic activity of bamboo-based porous carbon were investigated.The porous carbon was characterized by XPS,XRD,and alternating current impedance testing techniques to reveal its mechanism of action for the catalytic reduction of Cr(VI).The results showed that the optimum experimental conditions for the catalytic reduction of Cr(VI)by bamboo-based porous carbon were as follows:the initial concentration of Cr(VI)was 120 mg/L,the temperature was 60℃,the addition of ZH-100 carbon catalyst was 0.1 g,and the addition of reductant formic acid was 1.5 mL.Under these conditions,the reduction rate of Cr(VI)solution was up to 99.44%after 10 min of reaction.After three times of circulation,the catalytic reduction ability of ZH-100 decreased slightly,but the reduction rate was still able to achieve 99.22%reduction within 30 min.It was discovered that the removal of Cr(VI)involved physical adsorption and chemical reduction,with chemical reduction being the dominant process.The reasons for the decrease in catalyst performance after repeated use include the depletion of surface functional groups,the disorder of carbon microcrystals,and the increase of impedance.These indicated that the catalytic reduction mechanism of Cr(VI)by ZH-100 was functional group-mediated and graphite-like microcrystal-mediated.
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