共查询到18条相似文献,搜索用时 171 毫秒
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采用热分解法在钛基体上制备钌铱锡金属氧化物阳极,通过SEM、EDX、循环伏安、电化学阻抗谱及强化电解寿命试验等测试方法,探求不同海水温度对于钌铱锡金属氧化物阳极强化电解失效行为的影响规律。结果表明:在5~20 ℃海水温度条件下,阳极寿命短,失效阳极的中心区域存在少量残余涂层,呈现龟裂状形貌,而边缘地带Ti基体基本暴露,涂层发生局部电化学溶解或剥落;当海水电解温度为40 ℃时,阳极寿命较长,阳极涂层发生均匀电化学溶解。另外,随着海水温度的升高,阳极电化学活性表面积增大,稳定性逐渐提高。5~20 ℃条件下阳极失效主要是由于Ru组元的选择性溶解和涂层局部剥落导致,而40 ℃条件下涂层也发生电化学溶解,但TiO2钝化膜的形成是引起阳极失效的主要原因 相似文献
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主要考察Ti/Sb-SnO2/PbO2电极在Na2SO4溶液中恒电流密度长时间电解后,其电极表面状态的变化情况。通过扫描电镜与元素分析来考察电极表面形貌变化及表面元素分布情况,通过X射线衍射来考察电极表面氧化物的晶型变化情况,通过电感耦合等离子体仪来检测电解液中金属元素的浓度变化。结果表明,在长时间电解后,PbO2电极表面存在氧化物层溶蚀与脱落区域。在电解完成后的电解液中检测到Pb元素,表明电极表面存在Pb元素的溶解。X射线衍射表明电极表面仍然为PbO2层,只是相应的衍射峰强度有所降低。由上述结果推测PbO2电极失效的可能原因是:表层氧化物溶解、脱落以及基体的钝化。 相似文献
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《稀有金属材料与工程》2015,(11)
主要考察Ti/Sb-SnO_2/PbO_2电极在Na_2SO_4溶液中恒电流密度长时间电解后,其电极表面状态的变化情况。通过扫描电镜与元素分析来考察电极表面形貌变化及表面元素分布情况,通过X射线衍射来考察电极表面氧化物的晶型变化情况,通过电感耦合等离子体仪来检测电解液中金属元素的浓度变化。结果表明,在长时间电解后,PbO_2电极表面存在氧化物层溶蚀与脱落区域。在电解完成后的电解液中检测到Pb元素,表明电极表面存在Pb元素的溶解。X射线衍射表明电极表面仍然为PbO_2层,只是相应的衍射峰强度有所降低。由上述结果推测PbO_2电极失效的可能原因是:表层氧化物溶解、脱落以及基体的钝化。 相似文献
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测定了 PbO_2/Ti 电极在10%海水、天然海水、0.5NNa_2SO_4和5MNaCl 溶液中,温度25℃时的阳极极化曲线。在高电流密度范围内,它比 Pt/Ti 电极具有较低的氯和氧的过电位。该电极在上述介质中的消耗率比 Pt/Ti 阳极大,但远小于 Pb~2%Ag 阳极。这种电极已应用于阴极保护系统和次氯酸钠发生器中。 相似文献
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采用Pechini方法制备不同Sn含量的Ti/IrO2-Ta2O5-SnO2纳米氧化物阳极,并运用SEM、EDX、XRD等分析手段和析氧电位、循环伏安、强化电解等方法对阳极的表面形貌、微观结构和电化学性能进行研究。结果表明,制备的氧化物涂层由(IrSn)O2固溶体和非晶态的Ta2O5构成,组成与名义成分基本一致。随着Sn含量的增加,氧化物涂层表面裂纹增多。Sn的加入使Ti/IrO2-Ta2O5-SnO2氧化物阳极的析氧电位升高,稳定性降低。 相似文献
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The electrolytic plasma processing (EPP) process was employed to pretreat Ti substrates before applying Pt coating rather than using the conventional pickling route, resulting in increased efficiency and reduced environmental hazard. The successive anode-cathode EPP and single cathode EPP were used to pretreat the Ti substrate, respectively, and then the Ti/Pt anodes were prepared by the dip-coating/calcination method. The composition, morphology and electrochemical properties were investigated by X-ray diffraction, scanning electron microscopy and electrochemical workstation, respectively. The results show that the successive anode-cathode EPP-treated Ti substrate has uniform micro/nano-scale surface structure, and its corresponding Ti/Pt anode has the lowest impedance and best electrocatalytic activity among the Ti/Pt anodes prepared in this work. 相似文献
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1. IntroductionThe direct methanol fuel cell (DMFC) is a promising power source for electric vehicles[1--4] 5but its development is hampered by the large anodic overvoltage. For methanol, six electrons must be exchanged for complete oxidation and the oxidation kinetics is inherentlyslowed, so some illtermediates are formed during methanol oxidation. In fuel cells, as theplatinum alone is not a sufficiently active methanol oxidation electrocatalyst, Pt--basedmultimetallic catalysts earn the a… 相似文献
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采用热分解法制备了IrTa-X混合金属氧化物(MMO)涂层钛阳极。通过极化曲线研究了钛阳极的电化学性能,用SEM观察了涂层形貌,研究了阳极寿命与涂层厚度和电流密度之间的关系,并与国外阳极试样的寿命做了一对比。结果表明,所研制的涂层钛阳极具有良好的电化学性能和较长的使用寿命,是钢筋混凝土结构外加电流阴极保护中比较理想的辅助阳极。 相似文献
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IrO2+Ta2O5系钛基改性涂层阳极和失效特点 总被引:1,自引:0,他引:1
研究了Ti/(IrO2+Ta2O5)涂层阳极钛基表面不同改性条件下的表面形貌,截面扫描和界面元素分布,电解强化寿命和失效机理。结果表明,钛基体表面改性对涂层表面形貌没有根本性影响,表面改性的涂层阳极在槽电压-电解时间曲线上具有很长的平台期,显示出很好的强化寿命,平台期的主要失效特点在于涂层的电化学溶解,溶解从“龟裂”处始发,并且逐层进行。 相似文献
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对IrO2/Ti、SnIrO2/Ti、引进阳极3种涂层阳极的组织、结构、电化学性能、抗钝化性能进行了研究,并着重分析了Sn元素在涂层中所起的作用,结果表明添加Sn的IrO2/Ti阳极具备优异的电催化及抗钝化性能的结论,可作为硫酸中使用的电极材料. 相似文献
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Several different single-crystal superalloys were coated with different bond coatings to study the effect of composition on the cyclic oxidation lifetime of an yttria-stabilized zirconia (YSZ) top coating deposited by electron beam physical vapor deposition from a commercial source. Three different superalloys were coated with a 7 μm Pt layer that was diffused into the surface prior to YSZ deposition. One of the superalloys, N5, was coated with a low activity, Pt-modified aluminide coating and Pt-diffusion coatings with 3 and 7 μm of Pt. Three coatings of each type were furnace cycled to failure in 1 h cycles at 1150 °C to assess average coating lifetime. The 7 μm Pt diffusion coating on N5 had an average YSZ coating lifetime > 50% higher than a Pt-modified aluminide coating on N5. Without a YSZ coating, the Pt-modified aluminide coating on N5 showed the typical surface deformation during cycling, however, the deformation was greatly reduced when constrained by the YSZ coating. The 3 μm Pt diffusion coating had a similar average lifetime as the Pt-modified aluminide coating but a much wider scatter. The Pt diffusion bond coating on superalloy X4 containing Ti exhibited the shortest YSZ coating lifetime, this alloy-coating combination also showed the worst alumina scale adhesion without a YSZ coating. The third generation superalloy N6 exhibited the longest coating lifetime with a 7 μm Pt diffusion coating. 相似文献
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用两步法对钛基材进行阳极氧化,然后用阴极电沉积方法制备出纳米级铂镀层Ti/TiO2.Pt阳极,用场发射电子扫描显微镜(SE-SEM)分析了Pt沉积前后的表面形貌,并测试了其晶粒度。结果表明,Pt晶粒度大小为80nm~130nm,阳极不仅具有与铂阳极相似的电化学行为特征,而且通过Pt掺杂明显改善月.TiO2电极的电催化活性,并随着沉积Pt时间的增加,其电催化活性提高。 相似文献
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采用电沉积-热分解法制备了稀土铈掺杂锡锑阳极,利用SEM、EMPA、XRD、动电位扫描和循环伏安测定,研究了电极涂层形貌、元素组成分布、结构和选择催化性。结果表明:电极的电极涂层结构致密,氧化物分布均匀,基体覆盖完全;电极有较高的析氧电位,对苯酚有较好的催化降解作用,在对苯酚的降解测试中,苯酚的去除率达到100%,溶液化学耗氧量(COD)的降解率为97.7%,具有深度处理含酚废水的能力。 相似文献