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中空石墨碳材料作为电催化剂载体在直接乙醇燃料电池中的应用 总被引:1,自引:0,他引:1
以间苯二酚、苯酚与甲醛为前体,合成了一种中空石墨碳材料(hollow graphitic carbon,HGC).透射电镜(TEM)、N2吸附-脱附和Raman光谱测试结果表明,所制备的HGC为中孔结构,平均孔径为36nm.与商品Vulcan XC-72R相比,HGC中孔结构丰富,石墨化程度高.分别以HGC和XC-72R为载体制备了总金属载量为45%的PtSn/C电催化剂,X射线衍射和TEM结果表明这两个样品的平均粒径和晶格常数相近.单池性能测试表明,以45%PtSn/HGC为阳极催化剂的直接乙醇燃料电池的最大功率密度达到了62mW/cm2,与PtSn/XC-72R的54mW/cm2相比提高了近15%. 相似文献
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直接甲醇燃料电池电催化剂载体碳纳米带的合成与表征 总被引:2,自引:0,他引:2
以间苯二酚和甲醛为碳前体,合成了一种新型碳纳米材料碳纳米带(CNRs), 并采用透射电镜(TEM)、 X射线衍射(XRD)及氮气吸附/脱附测试对CNRs进行了结构表征. 结果表明,所合成的CNRs具有很高的石墨化程度及较规则的带状结构,带宽约为8~20 nm, BET比表面积为283 m2/g, 氮气等温线为type-Ⅳ型,表明CNRs为中孔结构,平均孔径约为8.2 nm. 以CNRs为载体通过多元醇法制备了45%PtRu/CNRs电催化剂,该催化剂与以Vulcan XC-72R为载体的PtRu电催化剂相比,直接甲醇燃料电池单池性能得到明显提高. 相似文献
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为改善电催化活性和亲水性,作者对商业碳黑(BP2000)进行了酸处理,获得了酸处理碳(ATC). 通过X光电子能谱、红外光谱、热重和接触角测试的表征方法证明了酸处理在碳表面产生了丰富的含氧基团. 本文首次利用紫外可见光谱测试了碱性条件抗坏血酸(AA)在空气中的化学氧化活化能,结果为37.1 kJ·mol-1. 另外,利用交流阻抗谱对碱性条件下ATC作为电催化剂时AA的氧化反应的活化能进行了评价. 碱性条件下,AA在单电池中有无ATC电催化剂层条件下的活化能分别为26.5和34.5 kJ·mol-1,活化能的降低表明ATC是一种有效的阳极电催化剂. 作者将ATC应用于直接碱性膜AA燃料电池(DAAFCs)作为阳极电催化剂,并且对DAAFC中一系列参数进行了优化,包括催化剂在膜(CCM)或气体扩散层(CDM)上的喷涂方法、阳极电催化剂的载量、阳极电催化剂中碱性聚合物的比例. 结果表明,采用CCM的膜电极制备方法、0.5 mg·cm-2的ATC载量、25wt%的碱性聚合物添加比例时,DAAFCs单池的功率密度可达18.5 mW·cm-2,远高于使用商品PtRu/C(5 mW·cm-2)做阳极电催化剂的单池. 在寿命测试中,使用溶解于1 mol·L-1 NaOH水溶液中的 0.5 mol·L-1 AA作为燃料(流速15 mL·min-1),DAAFCs单池的功率密度可以在25 min内维持在4 mW·cm-2以上(75 °C). 相似文献
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Alcohols fuel electro-oxidation is significant to the development of direct alcohols fuel cells, that are considered as a promising power source for portable electronic devices. Currently, the catalyst was restricted by the serious poisoning effect and high cost of noble metals. Developing low-cost Pt alloy with high performance and anti-CO poisoning ability was highly desired. In this work, PtCo-NC catalyst was synthesized by combining Pt nanoparticles with ZIF-67 after annealing in the tube furnace and the in situ generated N-doped carbon from ZIF-67 was functionalized to support the PtCo alloy nanoparticle. The structure and morphology were probed by X-ray diffraction, scanning electron microscope and transmission electron microscope, and the electrochemical performance was evaluated for alcohols of methanol and ethanol oxidation in the acid electrolyte. Compared with the reference sample of Pt/C, several times performance enhancement for alcohols fuel oxidation was found on PtCo-NC catalyst as well as the good catalytic stability. Specifically, the peak current density of PtCo-NC was 79.61 mA∙cm−2 for methanol oxidation, about 2.2 times higher than that of the Pt/C electrode (36.97 mA∙cm−2) and 2.5 times higher than that of the commercial Pt/C electrode (31.23 mA∙cm−2); it was 62.69 mA∙cm–2 for ethanol oxidation, about 1.65 times higher than that of Pt/C catalyst (37.99 mA∙cm−2) and commercial Pt/C electrode (37.77 mA∙cm−2). These catalytic performances were also much higher than some analogous catalysts developed for alcohols fuel oxidation. A much higher anti-CO poisoning ability was demonstrated by the CO stripping voltammetry experiment, in which the COad oxidation peak potential for PtCo-NC was 0.46 V, ca. 110 mV negative shift compared with Pt/C catalyst at 0.57 V. A strong electronic effect was indicated by the peak position shifting to the lower binding energy direction by 0.3 eV on PtCo-NC compared with Pt/C reference catalyst. According to the d-band center theory, the electron-enriched state of Pt will decrease the interaction strength of poisoning intermediates adsorbed on its surface; Moreover, according to the bifunctional catalytic mechanism, the presence of Co can form the adsorbed oxygen-containing species (―OH) more easily than Pt at low potentials, and this oxygen-species were helpful in the oxidation of COad at neighboring Pt sites. The high catalytic performance for alcohols fuel oxidation could be due to the largely improved anti-CO poisoning ability and the synergistic effect between the in situ formed PtCo nanoparticles and the N-doped carbon support. 相似文献
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直接甲醇燃料电池阳极催化剂的新体系: 纳米TiO2-CNT-PtNi复合纳米催化剂 总被引:6,自引:0,他引:6
采用电合成前驱体Ti(OEt)4直接水解法和电化学扫描电沉积法制备纳米TiO2-CNT-PtNi复合纳米催化剂. 透射电镜(TEM)和X射线衍射(XRD)测试结果表明, 纳米PtNi合金粒子(平均粒径8 nm)均匀地分散在纳米TiO2-CNT复合膜的三维网络结构中. 通过暂态电化学方法研究表明, 复合纳米催化剂的电化学活性比表面积为90 m2/g, 对甲醇氧化具有很高的电催化活性和稳定性, 常温常压下甲醇氧化峰电位为0.67和0.44 V, 当温度为60 ℃时, 氧化峰电位负移至0.64和0.30 V, 氧化峰电流密度高达1.38 A/cm2. 复合纳米催化剂对甲醇电氧化的高催化活性和稳定性可归因于多元复合纳米组分的协同催化作用, 这种作用导致CO在复合纳米催化剂上的弱吸附, 从而避免了催化剂的中毒. 相似文献
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直接甲醇燃料电池阳极催化剂的新体系: 纳米TiO2-CNT-PtNi复合纳米催化剂 总被引:2,自引:0,他引:2
采用电合成前驱体Ti(OEt)4直接水解法和电化学扫描电沉积法制备纳米TiO2-CNT-PtNi复合纳米催化剂.透射电镜(TEM)和X射线衍射(XRD)测试结果表明,纳米PtNi合金粒子(平均粒径8
nm)均匀地分散在纳米TiO2-CNT复合膜的三维网络结构中.通过暂态电化学方法研究表明,复合纳米催化剂的电化学活性比表面积为90
m2/g,对甲醇氧化具有很高的电催化活性和稳定性,常温常压下甲醇氧化峰电位为0.67和0.44
V,当温度为60℃时,氧化峰电位负移至0.64和0.30V,氧化峰电流密度高达1.38Mcm2.复合纳米催化剂对甲醇电氧化的高催化活性和稳定性可归因于多元复合纳米组分的协同催化作用,这种作用导致CO在复合纳米催化剂上的弱吸附,从而避免了催化剂的中毒. 相似文献
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Fei Ye Shengzhou Chen Xinfa Dong Weiming Lin 《天然气化学杂志》2007,16(2):162-166
Carbon nanotubes (CNTs) supported Pt-Ru and Pt-Ru-Ni catalysts were prepared by chemical reduction of metal precursors with sodium borohydride at room temperature. The crystallographic properties and composition of the catalysts were characterized by X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis, and the catalytic activity and stability for methanol electro-oxidation were measured by electrochemical impedance spectroscopy (EIS), linear sweep voltammetries (LSV), and chronoamperometry (CA). The results show that the catalysts exhibit face-centered cubic (fcc) structure. The particle size of Pt-Ru-Ni/CNTs catalyst is about 4.8 nm. The catalytic activity and stability of the Pt-Ru-Ni/CNTs catalyst are higher than those of Pt-Ru/CNTs catalyst. 相似文献
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快速功能化碳纳米管载 Pt 催化剂的醇氧化性能(英文) 总被引:1,自引:0,他引:1
采用HF刻蚀及交替微波加H2O2相结合的方法进行快速功能化碳纳米管(CNTs),应用红外光谱、拉曼光谱和透射电镜等方法详细考察了CNTs及其载Pt催化剂的物化性质,并采用循环伏安法、线性电流扫描法和计时电流法考察了所得催化剂的电化学性能.结果表明,CNTs经过HF刻蚀和交替微波H2O2双重处理后更适合用作催化剂载体,以10s-on/20s-off加热5次所得CNTs载Pt催化剂显示出最佳的催化性能.这可归因于处理后的CNTs表面含有丰富的微孔及含氧官能团,能有效增强Pt颗粒及CNTs间的相互作用. 相似文献
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直接甲醇燃料电池Pt-Ru/C催化剂的稳定性 总被引:1,自引:2,他引:1
采用单电池寿命测试和电化学快速老化两种方法考察了直接甲醇燃料电池阳极电催化剂Pt-Ru/C的稳定性,研究了电池实际运行条件下催化剂微观形貌的变化对电池性能的影响. 结果表明,Pt-Ru/C催化剂做成膜电极后,粒径由2.8 nm增大到3.8 nm,催化剂的粒径随放电时间的延长有增大的趋势,连续放电320 h,粒径增大到5.8 nm. 采用电化学方法能够快速地评价催化剂的稳定性,大大缩短催化剂稳定性评价的周期,有利于催化剂的制备和筛选. 相似文献
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碳是重要的能量载体. 直接碳固体氧化物燃料电池(DC-SOFC)是一种直接使用固体碳为燃料的能量转换装置,通过电化学反应,DC-SOFC可将碳所蕴含的化学能直接而连续地转换成电能,转换效率高,产生的CO2浓度高,易于捕集和后续处理. 本文系统地介绍DC-SOFC的结构组成、工作原理、研究现状和发展趋势,重点介绍了作者课题组在DC-SOFC研究方面的成果和进展,包括单电池和电池组的研制、采用生物质碳和煤炭为燃料时的性能和DC-SOFC在气电联产中的应用探索. 相似文献