Methodology for the electrochemical decomposition of imazethapyr using Ti/SnO2-Sb2O5/PbO2 anode in Na2SO4 medium is suggested in this paper. The electrolysis reaction conditions were optimized. The process of electroc...Methodology for the electrochemical decomposition of imazethapyr using Ti/SnO2-Sb2O5/PbO2 anode in Na2SO4 medium is suggested in this paper. The electrolysis reaction conditions were optimized. The process of electrochemical decomposition was monitored by ultra-violet spectrophotometry and CODCr method. The electrochemical decomposition mechanism of imazethapyr was studied primarily by UV-VIS spectrophotometry. The effectiveness of the electrochemical pretreatment was proved by the comparative aerobic biological treatment test based on the activated sludge process.展开更多
目前在电化学氧化处理法降解苯酚废水的研究过程中,研究者多将重心放在活性电极的探索及制备上,而对于反应器的开发鲜有报道。就这一问题,本文研究了新型微流控反应器中苯酚的电化学降解效果。电化学氧化实验在装有Ti/SnO2-Sb2O5阳极的...目前在电化学氧化处理法降解苯酚废水的研究过程中,研究者多将重心放在活性电极的探索及制备上,而对于反应器的开发鲜有报道。就这一问题,本文研究了新型微流控反应器中苯酚的电化学降解效果。电化学氧化实验在装有Ti/SnO2-Sb2O5阳极的微型流通池中操作进行,实验对循环体系的体积流率ΦV、电极间距h的影响进行了考察。结果表明,当流通电解槽中的阴阳极间距采用微米级尺寸时,苯酚的阳极氧化反应取得了较快的氧化速度。在i=20 m A/cm2、ΦV=0.54 m L/min的电解条件下,电解2~3h苯酚去除率即可达到90%以上,相同流速下电极间距h越小降解速率越快。且由数据回归得到了苯酚的一系列随h的减小而增大的准一级反应的反应速率常数。这一结论表明微流控电解槽内的苯酚降解过程主要传质控制过程。展开更多
PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffracti...PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffraction,transmission electron microscopy and the catalytic activity toward formic acid electro-oxidation in acid medium investigated by cyclic voltammetry(CV),chroamperometry(CA)and tests on direct formic acid fuel cell(DFAFC)at 100℃.X-ray diffractograms of PdAuIr/C-Sb2O5·SnO2electrocatalysts showed the presence of Pd fcc phase,Pd-Au fcc alloys,carbon and ATO phases,while Ir phases were not observed.TEM micrographs and histograms indicated that the nanoparticles were not well dispersed on the support and some agglomerates.The cyclic voltammetry and chroamperometry studies showed that PdAuIr/C-Sb2O5·SnO2(50∶45∶5)had superior performance toward formic acid electro-oxidation at 25℃compared to PdAuIr/C-Sb2O5·SnO2(70∶20∶10),PdAuIr/C-Sb2O5·SnO2(90∶5∶5)and Pd/C-Sb2O5·SnO2electrocatalysts.The experiments in a single DFAFC also showed that all PdAuIr/C-Sb2O5·SnO2electrocatalysts exhibited higher performance for formic acid oxidation in comparison with Pd/C-Sb2O5·SnO2electrocatalysts,however PdAuIr/C-Sb2O5·SnO2(90∶5∶5)had superior performance.These results indicated that the addition of Au and Ir to Pd favor the electro-oxidation of formic acid,which could be attributed to the bifunctional mechanism(the presence of ATO,Au and Ir oxides species)associated to the electronic effect(Pd-Au fcc alloys).展开更多
The Ti/SnO2 Sb2O4 electrode has been prepared by the electroplate sinter method. The effect of SbCl3 adding amount and sintering temperature on its electrode lifetime and oxygen evolution potential were investigated b...The Ti/SnO2 Sb2O4 electrode has been prepared by the electroplate sinter method. The effect of SbCl3 adding amount and sintering temperature on its electrode lifetime and oxygen evolution potential were investigated by means of EDX, SEM and XRD analysis. The results indicated that the electrode appeared the best performance when the SbCl3 adding amounts was 0.2g and the sintering temperature was 550℃. In optimized conditions Ti substrate was entirely covered by SnO2 Sb2O4 and the combinations among them were tight. Due to the use of electroplate method, the electrical conductivity, the oxygen evolution potential and the electrode lifetime were increased, so the electro catalytic activity and the electrochemical stability of the prepared electrode were found to be superior.展开更多
采用溶胶-凝胶法和化学沉积法制备了Li4Ti4.75Cu0.25O12/SnO2复合活性材料。通过X射线衍射（XRD）、扫描电镜（SEM）、恒流充放电测试对材料进行结构、形貌表征及电化学性能测试。结果表明：Li4Ti4.75Cu0.25O12/SnO2复合活性物质能够进...采用溶胶-凝胶法和化学沉积法制备了Li4Ti4.75Cu0.25O12/SnO2复合活性材料。通过X射线衍射（XRD）、扫描电镜（SEM）、恒流充放电测试对材料进行结构、形貌表征及电化学性能测试。结果表明：Li4Ti4.75Cu0.25O12/SnO2复合活性物质能够进一步改善倍率性能的同时,循环性能也得到了很好的保证。当电压在1~3 V时,电流密度为1C倍率条件下,Li4Ti4.75Cu0.25O12/SnO2复合材料首次放电比容量高达202.55 m A·h/g。经过50次循环后,容量仍保持在202.51 m A·h/g,容量保持率高达99.98%。展开更多
文摘Methodology for the electrochemical decomposition of imazethapyr using Ti/SnO2-Sb2O5/PbO2 anode in Na2SO4 medium is suggested in this paper. The electrolysis reaction conditions were optimized. The process of electrochemical decomposition was monitored by ultra-violet spectrophotometry and CODCr method. The electrochemical decomposition mechanism of imazethapyr was studied primarily by UV-VIS spectrophotometry. The effectiveness of the electrochemical pretreatment was proved by the comparative aerobic biological treatment test based on the activated sludge process.
文摘目前在电化学氧化处理法降解苯酚废水的研究过程中,研究者多将重心放在活性电极的探索及制备上,而对于反应器的开发鲜有报道。就这一问题,本文研究了新型微流控反应器中苯酚的电化学降解效果。电化学氧化实验在装有Ti/SnO2-Sb2O5阳极的微型流通池中操作进行,实验对循环体系的体积流率ΦV、电极间距h的影响进行了考察。结果表明,当流通电解槽中的阴阳极间距采用微米级尺寸时,苯酚的阳极氧化反应取得了较快的氧化速度。在i=20 m A/cm2、ΦV=0.54 m L/min的电解条件下,电解2~3h苯酚去除率即可达到90%以上,相同流速下电极间距h越小降解速率越快。且由数据回归得到了苯酚的一系列随h的减小而增大的准一级反应的反应速率常数。这一结论表明微流控电解槽内的苯酚降解过程主要传质控制过程。
基金the Laboratório de Microscopia do Centro de Ciências e Tecnologia de Materiais(CCTM) by TEM measurements,FAPESP(2011/18246-0,2012/03516-5) and CNPQ(150639/2013-9)for the financial support
文摘PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffraction,transmission electron microscopy and the catalytic activity toward formic acid electro-oxidation in acid medium investigated by cyclic voltammetry(CV),chroamperometry(CA)and tests on direct formic acid fuel cell(DFAFC)at 100℃.X-ray diffractograms of PdAuIr/C-Sb2O5·SnO2electrocatalysts showed the presence of Pd fcc phase,Pd-Au fcc alloys,carbon and ATO phases,while Ir phases were not observed.TEM micrographs and histograms indicated that the nanoparticles were not well dispersed on the support and some agglomerates.The cyclic voltammetry and chroamperometry studies showed that PdAuIr/C-Sb2O5·SnO2(50∶45∶5)had superior performance toward formic acid electro-oxidation at 25℃compared to PdAuIr/C-Sb2O5·SnO2(70∶20∶10),PdAuIr/C-Sb2O5·SnO2(90∶5∶5)and Pd/C-Sb2O5·SnO2electrocatalysts.The experiments in a single DFAFC also showed that all PdAuIr/C-Sb2O5·SnO2electrocatalysts exhibited higher performance for formic acid oxidation in comparison with Pd/C-Sb2O5·SnO2electrocatalysts,however PdAuIr/C-Sb2O5·SnO2(90∶5∶5)had superior performance.These results indicated that the addition of Au and Ir to Pd favor the electro-oxidation of formic acid,which could be attributed to the bifunctional mechanism(the presence of ATO,Au and Ir oxides species)associated to the electronic effect(Pd-Au fcc alloys).
文摘The Ti/SnO2 Sb2O4 electrode has been prepared by the electroplate sinter method. The effect of SbCl3 adding amount and sintering temperature on its electrode lifetime and oxygen evolution potential were investigated by means of EDX, SEM and XRD analysis. The results indicated that the electrode appeared the best performance when the SbCl3 adding amounts was 0.2g and the sintering temperature was 550℃. In optimized conditions Ti substrate was entirely covered by SnO2 Sb2O4 and the combinations among them were tight. Due to the use of electroplate method, the electrical conductivity, the oxygen evolution potential and the electrode lifetime were increased, so the electro catalytic activity and the electrochemical stability of the prepared electrode were found to be superior.
文摘采用溶胶-凝胶法和化学沉积法制备了Li4Ti4.75Cu0.25O12/SnO2复合活性材料。通过X射线衍射（XRD）、扫描电镜（SEM）、恒流充放电测试对材料进行结构、形貌表征及电化学性能测试。结果表明：Li4Ti4.75Cu0.25O12/SnO2复合活性物质能够进一步改善倍率性能的同时,循环性能也得到了很好的保证。当电压在1~3 V时,电流密度为1C倍率条件下,Li4Ti4.75Cu0.25O12/SnO2复合材料首次放电比容量高达202.55 m A·h/g。经过50次循环后,容量仍保持在202.51 m A·h/g,容量保持率高达99.98%。
