针对鲁奇炉煤气化废水中酚类污染物难降解而无法满足生化处理的难题,采用热化学法制备钛铱钽催化电极(Ti/IrO2-Ta2O5),并将其作为阳极对鲁奇炉煤气化废水进行电催化降解。结果表明,当电流密度为50 m A/cm2、NaCl质量浓度为9.5 g/L、pH为...针对鲁奇炉煤气化废水中酚类污染物难降解而无法满足生化处理的难题,采用热化学法制备钛铱钽催化电极(Ti/IrO2-Ta2O5),并将其作为阳极对鲁奇炉煤气化废水进行电催化降解。结果表明,当电流密度为50 m A/cm2、NaCl质量浓度为9.5 g/L、pH为4、降解时间为180 min时,苯酚和COD的去除率较高,分别可达92%和48%。废水色度极大降低,BOD/COD提高至0.42,降解后的废水可满足生化处理要求。动力学研究表明,废水降解过程符合表观一级反应的动力学规律。展开更多
采用外加电源模拟燃料电池反极,通过极化曲线和电化学交流阻抗(EIS)测试分析反极前后电化学性能和电阻变化。常规Pt/C电极4次反极后,0.5 A/cm^2电流密度下,电压下降274.2 m V,说明反极对其造成致命伤害,性能急剧衰减。在催化层引入IrO2...采用外加电源模拟燃料电池反极,通过极化曲线和电化学交流阻抗(EIS)测试分析反极前后电化学性能和电阻变化。常规Pt/C电极4次反极后,0.5 A/cm^2电流密度下,电压下降274.2 m V,说明反极对其造成致命伤害,性能急剧衰减。在催化层引入IrO2,经过4次反极,性能无明显衰减,说明加入IrO2具有明显的抗反极作用,尤其是氢气侧加入Ir O2后具有较好的抗反极能力,经过4次反极测试后,电压下降小于9.6 m V。分析了IrO2在反极中起到抑制作用的原因。展开更多
In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the sur...In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the surface properties and electrochemical behavior of electrodes,we performed physical characterizations and electrochemical measurements.The obtained results revealed that the binary oxide coating was composed of rutile IrO2,amorphous ZrO2,and an IrO2–ZrO2 solid solution.The IrO2–ZrO2 binary oxide coatings exhibited cracked structures with flat regions.A slight incorporation of ZrO2 promoted the crystallization of the active component IrO2.However,the crystallization of IrO2 was hindered when the added ZrO2 content was greater than 30at%.The appropriate incorporation of ZrO2 enhanced the electrocatalytic performance of the pure IrO2 coating.The Ti/70at%IrO2–30at%ZrO2 electrode,with its large active surface area,improved electrocatalytic activity,long service lifetime,and especially,lower cost,is the most effective for promoting oxygen evolution in sulfuric acid solution.展开更多
IrO2 and IrRuOx(Ir:Ru 60:40 at%),supported by 50 wt%onto titania nanotubes(TNTs)and(3 at%Nb)Nb-doped titania nanotubes(Nb-TNTs),as electrocatalysts for the oxygen evolution reaction(OER),were synthesized and character...IrO2 and IrRuOx(Ir:Ru 60:40 at%),supported by 50 wt%onto titania nanotubes(TNTs)and(3 at%Nb)Nb-doped titania nanotubes(Nb-TNTs),as electrocatalysts for the oxygen evolution reaction(OER),were synthesized and characterized by means of structural,surface analytical and electrochemical techniques.Nb doping of titania significantly increased the surface area of the support from 145(TNTs)to 260 m2g-1(Nb-TNTs),which was significantly higher than those of the Nb-doped titania supports previously reported in the literature.The surface analytical techniques showed good dispersion of the catalysts onto the supports.The X-ray photoelectron spectroscopy analyses showed that Nb was mainly in the form of Nb(IV)species,the suitable form to behave as a donor introducing free electrons to the conduction band of titania.The redox transitions of the cyclic voltammograms,in agreement with the XPS results,were found to be reversible.Despite the supported materials presented bigger crystallite sizes than the unsupported ones,the total number of active sites of the former was also higher due to their better catalyst dispersion.Considering the outer and the total charges of the cyclic voltammograms in the range 0.1–1.4 V,stability and electrode potentials at given current densities,the preferred catalyst was Ir O2 supported on the Nb-TNTs.The electrode potentials corresponding to given current densities were between the smallest ones given in the literature despite the small oxide loading used in this work and its Nb doping,thus making the Nb-TNTs-supported IrO2 catalyst a promising candidate for the OER.The good dispersion of IrO2,high specific surface area of the Nb-doped supports,accessibility of the electroactive centers,increased stability due to Nb doping and electron donor properties of the Nb(IV)oxide species were considered the main reasons for its good performance.展开更多
文摘针对鲁奇炉煤气化废水中酚类污染物难降解而无法满足生化处理的难题,采用热化学法制备钛铱钽催化电极(Ti/IrO2-Ta2O5),并将其作为阳极对鲁奇炉煤气化废水进行电催化降解。结果表明,当电流密度为50 m A/cm2、NaCl质量浓度为9.5 g/L、pH为4、降解时间为180 min时,苯酚和COD的去除率较高,分别可达92%和48%。废水色度极大降低,BOD/COD提高至0.42,降解后的废水可满足生化处理要求。动力学研究表明,废水降解过程符合表观一级反应的动力学规律。
文摘采用外加电源模拟燃料电池反极,通过极化曲线和电化学交流阻抗(EIS)测试分析反极前后电化学性能和电阻变化。常规Pt/C电极4次反极后,0.5 A/cm^2电流密度下,电压下降274.2 m V,说明反极对其造成致命伤害,性能急剧衰减。在催化层引入IrO2,经过4次反极,性能无明显衰减,说明加入IrO2具有明显的抗反极作用,尤其是氢气侧加入Ir O2后具有较好的抗反极能力,经过4次反极测试后,电压下降小于9.6 m V。分析了IrO2在反极中起到抑制作用的原因。
基金financially supported by the National Natural Science Foundation of China (Nos. U1802253, 51974025 and 51674026)the Guangxi Innovation-Driven Development Project (No. AA18242042-1)+1 种基金the Beijing Natural Science Foundation of China (No. 2182040)the Fundamental Research Funds for the Central Universities (FRF22TT-19-001)
文摘In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the surface properties and electrochemical behavior of electrodes,we performed physical characterizations and electrochemical measurements.The obtained results revealed that the binary oxide coating was composed of rutile IrO2,amorphous ZrO2,and an IrO2–ZrO2 solid solution.The IrO2–ZrO2 binary oxide coatings exhibited cracked structures with flat regions.A slight incorporation of ZrO2 promoted the crystallization of the active component IrO2.However,the crystallization of IrO2 was hindered when the added ZrO2 content was greater than 30at%.The appropriate incorporation of ZrO2 enhanced the electrocatalytic performance of the pure IrO2 coating.The Ti/70at%IrO2–30at%ZrO2 electrode,with its large active surface area,improved electrocatalytic activity,long service lifetime,and especially,lower cost,is the most effective for promoting oxygen evolution in sulfuric acid solution.
文摘IrO2 and IrRuOx(Ir:Ru 60:40 at%),supported by 50 wt%onto titania nanotubes(TNTs)and(3 at%Nb)Nb-doped titania nanotubes(Nb-TNTs),as electrocatalysts for the oxygen evolution reaction(OER),were synthesized and characterized by means of structural,surface analytical and electrochemical techniques.Nb doping of titania significantly increased the surface area of the support from 145(TNTs)to 260 m2g-1(Nb-TNTs),which was significantly higher than those of the Nb-doped titania supports previously reported in the literature.The surface analytical techniques showed good dispersion of the catalysts onto the supports.The X-ray photoelectron spectroscopy analyses showed that Nb was mainly in the form of Nb(IV)species,the suitable form to behave as a donor introducing free electrons to the conduction band of titania.The redox transitions of the cyclic voltammograms,in agreement with the XPS results,were found to be reversible.Despite the supported materials presented bigger crystallite sizes than the unsupported ones,the total number of active sites of the former was also higher due to their better catalyst dispersion.Considering the outer and the total charges of the cyclic voltammograms in the range 0.1–1.4 V,stability and electrode potentials at given current densities,the preferred catalyst was Ir O2 supported on the Nb-TNTs.The electrode potentials corresponding to given current densities were between the smallest ones given in the literature despite the small oxide loading used in this work and its Nb doping,thus making the Nb-TNTs-supported IrO2 catalyst a promising candidate for the OER.The good dispersion of IrO2,high specific surface area of the Nb-doped supports,accessibility of the electroactive centers,increased stability due to Nb doping and electron donor properties of the Nb(IV)oxide species were considered the main reasons for its good performance.
