A novel catalyst for CO2 electroreduction based on nanostructured SnO2 was synthesized using a facile hydrothermal self-assembly method. The electrochemical activity showed that the catalyst gave outstanding catalytic...A novel catalyst for CO2 electroreduction based on nanostructured SnO2 was synthesized using a facile hydrothermal self-assembly method. The electrochemical activity showed that the catalyst gave outstanding catalytic activity and selectivity in CO2 electroreduction. The catalytic activity and formate selectivity depended strongly on the electrolyte conditions. A high faradaic efficiency, i.e., 56%, was achieved for formate formation in KHCO3 （0.5 mol/L）. This is attributed to control of formate production by mass and charge transfer processes. Electrolysis experiments using SnO2-50/GDE （an SnOz-based gas-diffusion electrode, where 50 indicates the 50% ethanol content of the electrolyte） as the catalyst, showed that the electrolyte pH also affected CO2 reduction. The optimum electrolyte pH for obtaining a high faradaic efficiency for formate production was 8.3. This is mainly because a neutral or mildly alkaline environment maintains the oxide stability. The fara- daic efficiency for formate production declined with time. X-ray photoelectron spectroscopy showed that this is the result of deposition of trace amounts of fluoride ions on the SnO2-50/GDE surface, which hinders reduction of CO2 to formate.展开更多
采用UASB处理以甲醇为有机溶剂的对乙酰氨基苯璜酰氯(p-ASC)生产废水。通过逐步减少HRT,考察有机负荷(OLR)从2.0 g COD/(L·d)逐步提高到24.0 g COD/(L·d)过程中反应器处理效果的变化。结果表明,在最优的OLR 7.0 g COD/(L·...采用UASB处理以甲醇为有机溶剂的对乙酰氨基苯璜酰氯(p-ASC)生产废水。通过逐步减少HRT,考察有机负荷(OLR)从2.0 g COD/(L·d)逐步提高到24.0 g COD/(L·d)过程中反应器处理效果的变化。结果表明,在最优的OLR 7.0 g COD/(L·d)的条件下,p-ASC和COD的去除率分别能达到76%和100%。虽然进水没有硫酸盐,但是出水却有硫化物和硫酸盐的产生。进一步保持最优的OLR条件下的HRT(0.45 d)不变,逐步增加进水p-ASC浓度到1 100 mg/L,产甲烷菌没有发现受到抑制。持续增加进水硫酸盐浓度到3 000 mg/L,发现硫酸盐还原菌没有受到抑制,但是产甲烷菌却受到抑制,最后减少硫酸盐浓度到1 000 mg/L,厌氧系统在1周后几乎完全恢复。展开更多
基金supported by the Innovation Program of the Shanghai Municipal Education Commission(14ZZ074)the International Academic Coop-eration and Exchange Program of Shanghai Science and Technology Committee(14520721900)+1 种基金Graduate Innovation Fund of Donghua University(15D311304)the College of Environmental Science and Engineering,State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry,Donghua University.All the financial supports are gratefully acknowledged~~
文摘A novel catalyst for CO2 electroreduction based on nanostructured SnO2 was synthesized using a facile hydrothermal self-assembly method. The electrochemical activity showed that the catalyst gave outstanding catalytic activity and selectivity in CO2 electroreduction. The catalytic activity and formate selectivity depended strongly on the electrolyte conditions. A high faradaic efficiency, i.e., 56%, was achieved for formate formation in KHCO3 （0.5 mol/L）. This is attributed to control of formate production by mass and charge transfer processes. Electrolysis experiments using SnO2-50/GDE （an SnOz-based gas-diffusion electrode, where 50 indicates the 50% ethanol content of the electrolyte） as the catalyst, showed that the electrolyte pH also affected CO2 reduction. The optimum electrolyte pH for obtaining a high faradaic efficiency for formate production was 8.3. This is mainly because a neutral or mildly alkaline environment maintains the oxide stability. The fara- daic efficiency for formate production declined with time. X-ray photoelectron spectroscopy showed that this is the result of deposition of trace amounts of fluoride ions on the SnO2-50/GDE surface, which hinders reduction of CO2 to formate.
文摘采用UASB处理以甲醇为有机溶剂的对乙酰氨基苯璜酰氯(p-ASC)生产废水。通过逐步减少HRT,考察有机负荷(OLR)从2.0 g COD/(L·d)逐步提高到24.0 g COD/(L·d)过程中反应器处理效果的变化。结果表明,在最优的OLR 7.0 g COD/(L·d)的条件下,p-ASC和COD的去除率分别能达到76%和100%。虽然进水没有硫酸盐,但是出水却有硫化物和硫酸盐的产生。进一步保持最优的OLR条件下的HRT(0.45 d)不变,逐步增加进水p-ASC浓度到1 100 mg/L,产甲烷菌没有发现受到抑制。持续增加进水硫酸盐浓度到3 000 mg/L,发现硫酸盐还原菌没有受到抑制,但是产甲烷菌却受到抑制,最后减少硫酸盐浓度到1 000 mg/L,厌氧系统在1周后几乎完全恢复。
