应《网络安全法》要求，自2017年10月1日起，未进行实名认证将不得使用互联网跟帖服务。为保障您的帐号能够正常使用，请尽快对帐号进行手机号验证，感谢您的理解与支持！

24小时热门版块排行榜    

小木虫论坛-学术科研互动平台 » 化学化工区 » 电化学 » 电分析测试 » 【求助】关于燃料电池钯催化剂
51/1返回列表
查看: 633  |  回复: 4
只看楼主 @他人 存档 新回复提醒 (忽略) 收藏    在APP中查看
当前主题已经存档。
【有奖交流】积极回复本帖子，参与交流，就有机会分得作者 伊珑静 的 10 个金币

伊珑静

铜虫 (小有名气)

[交流] 【求助】关于燃料电池钯催化剂

请教各位大侠,用RHE电极作为参比电极，用了测钯催化剂的氢吸附，为什么会bulk hydride formation，这些氢化物是怎么形成的，而且beta-phase hydride和alfa-phase hydride各是什么，为什么它们起峰的位置还不同？
回复此楼

» 收录本帖的淘帖专辑推荐

新能源

» 猜你喜欢
1楼 2010-01-17 18:27:57
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

zhongma88619

木虫 (著名写手)
呵呵！！！！还有英语，翻译一下！！！！
赞一下 回复此楼
我的智商已经超过了我的身高！
2楼2010-01-17 19:45:36
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

yjfeng2000

木虫 (著名写手)
★ ★ ★ ★ ★ ★ ★ ★ ★ ★
伊珑静(金币+10,VIP+0): 1-19 20:05
钯本身是一个很好的储氢材料,一般合成钯都是通过氢气还原的方法,所以这个钯催化剂本身就有PdHx相存在.建议你看看下面的参考文献.
Flanagan, T. B. and S. Luo (2006). "Thermodynamics of Hydrogen Solution and Hydride Formation in Pd−Mn Alloys. 1. Disordered Alloys and a Correlation Effect." The Journal of Physical Chemistry B 110(15): 8080-8086.
        The thermodynamics of H2 solution and hydride formation/decomposition have been determined by reaction calorimetry (303 K) for disordered face centered cubic (fcc) PdMn alloys. This alloy system belongs to the expanded lattice category which predicts that and DeltaHplat for H2 absorption should be more exothermic than those for Pd; the experimental results are that the former is more exothermic, at least at the higher Mn contents, but the latter is not. There is a regular decrease in the H capacity (at pH2 = 0.2 MPa) with atom fraction Mn. A linear dependence of log pH2 upon H content is found in the single hydride phase for all of these alloys suggesting that DeltaHH and DeltaSH are also linear functions of r in this region. This is confirmed using the Pd0.875Mn0.125 alloy which has no two-phase region (303 K). It is shown for the Pd0.875Mn0.125 alloy and for Pd that the changes of partial enthalpies and entropies with H content are correlated so as to minimize changes of muH.

Flanagan, T. B. and W. A. Oates (1991). "The palladium-hydrogen system." Annu. Rev. Mater. Sci. 21: 269-304.
            In this review an attempt is made to highlight some of the important properties of the palladium-hydrogen system. (The term hydrogen will be used as a collective term when referring to all three isotopes, but otherwise the names of the specific isotopes, protium, deuterium, and tritium, will be used.) Most of the data in the literature are for the palladium-protium system; generally the three isotopes behave similarly, however, the thermodynamic and kinetic (diffusion) behavior of the isotopes differ quantitatively and these differences are discussed below.
    Lasser recently published a monograph entitled Tritium and Helium-3 in Metals (1), which contains a compilation of the thermodynamic properties of all three isotopes in palladium and in palladium-silver alloys. Lewis presented a comprehensive review in 1966 (2), certain aspects which he has updated (3). Wicke & Brodowsky (4) reviewed the thermodynamic and kinetic behavior ofpalladlum-hydrogen and palladium alloyhydrogen systems in 1978. In view of the interest in this system, kindled by the recent discovery of possible anomalous effects in the Pd-D sYstem, it appears to be a timely occasion to review the palladium-hydrogen system.
   The palladium-hydrogen system has long held a key role in metal-hydrogen systems because it is the system in which reliable experimental data can most easily be obtained. Palladium can be obtained in a quite pure state with negligibly small interstitial, e.g. O, C, N, impurity levels, and no special surface treatments are needed to obtain equilibrium between the gaseous and solid phases, in marked contrast to most other metalhydrogen systems. Results from this key system have provided the paths that have assisted in the characterization and understanding of other metal-hydrogen systems.

Kobayashi, H., M. Yamauchi, et al. (2008). "Hydrogen Absorption in the Core/Shell Interface of Pd/Pt Nanoparticles." Journal of the American Chemical Society 130(6): 1818-1819.
        We have investigated the hydrogen absorption behavior of Pd/Pt nanoparticles with a core/shell-type structure. From the results of the hydrogen pressurecomposition (PC) isotherm and solid-state 2H NMR measurements, it was revealed that the Pd/Pt nanoparticles can absorb hydrogen, and most of the absorbed hydrogen atoms are situated around the interfacial region between the Pd core and the Pt shell of the Pd/Pt nanoparticles, indicating that the core/shell boundary plays an important role in the formation of the hydride phase of the Pd/Pt nanoparticles.

Kobayashi, H., M. Yamauchi, et al. (2008). "On the Nature of Strong Hydrogen Atom Trapping Inside Pd Nanoparticles." Journal of the American Chemical Society 130(6): 1828-1829.
        We have investigated the hydrogen absorption/desorption hysteresis by means of in situ powder X-ray diffraction (XRD) and solid-state 2H NMR to clarify the location of hydrogen, surface or body, and its chemical form, molecular, atomic, or as hydride. The present results point out that strongly trapped hydrogen atoms exist inside the Pd nanoparticles due to a strong PdH bond formation and are stabilized in the lattice of Pd nanoparticles, compared to bulk Pd.

Lebouin, C., Y. Soldo-Olivier, et al. (2009). "Evidence of the Substrate Effect in Hydrogen Electroinsertion into Palladium Atomic Layers by Means of in Situ Surface X-ray Diffraction." Langmuir in press(0): 10.1021/la803913e.
        In this work, we report an in situ surface X-ray diffraction study of the hydrogen electroinsertion in a two-monolayer equivalent palladium electrodeposit on Pt(111). The role of chloride in the deposition solution in favoring layer-by-layer film growth is evidenced. Three Pd layers are necessary to describe the deposit structure correctly, but the third-layer occupancy is quite low, equal to about 0.22. As a major result, resistance to hydriding of the two atomic Pd layers closest to the Pt interface is observed, which is linked to a strong effect of the Pt(111) substrate. As a consequence, we observe the lowering of the total hydride stoichiometry compared to bulk Pd. Our measurements also reveal good reversibility of the deposit structure, at least toward one hydrogen insertion鈭抎esorption cycle.

Luo, S., A. Craft, et al. (2006). "Thermodynamics of Hydrogen Solution and Hydride Formation in Pd−Mn Alloys. 2. Ordered Alloys." The Journal of Physical Chemistry B 110(15): 8087-8093.
        There are marked differences in H2 solubilities between ordered and disordered PdMn alloys with the largest difference found between the L12 and the disordered form of the Pd3Mn alloy. The thermodynamics of H2 solution have been determined for the L12 form, the long-period superstructure (lps), and the disordered forms of the Pd0.80Mn0.20 and Pd0.75Mn0.25(Pd3Mn) alloys. Relative partial molar enthalpies and entropies were determined mainly by reaction calorimetry over the range of H contents accessible from pH2 10 Pa to 0.3 MPa (303 K). The enthalpies for absorption of H2 are more exothermic over most of the range of H contents for the L12 forms of the Pd3Mn and Pd0.80Mn0.20 alloys than for their other forms. The reaction enthalpies are constant across a relatively wide range of H contents for the L12 form of the Pd0.80Mn0.20 and Pd3Mn alloys indicating that there are two-phase coexistence regions (303 K). The HH attractive interaction, which leads to hydride formation, is much greater for the L12 than for the other forms of the Pd3Mn alloy and for Pd itself. It has been found that the HH interaction always decreases in magnitude and, accompanying this, the THS (terminal hydrogen solubility) always increases by alloying Pd.1 The L12 ordered Pd3Mn alloy is an exception to this, and therefore, the generalization about THS must be restricted to disordered face centered cubic (fcc) Pd alloys.

Sa, J., G. D. Arteaga, et al. (2006). "Factors Influencing Hydride Formation in a Pd/TiO2 Catalyst." The Journal of Physical Chemistry B 110(34): 17090-17095.
        A sample containing Pd nanoparticles deposited on TiO2 was subjected to a series of different thermal pretreatments. The range of these treatments was selected to provide a palladium surface in a number of different states, including a form where TiOx overlayers had been formed. Experiments were conducted to determine how the state of the Pd surface influenced the formation of Pd hydride. The amount of hydrogen released during a temperature-programmed experiment was used to quantify the extent of Pd beta-hydride formation following room-temperature exposure to hydrogen. Samples were characterized by HAADF (high-angle annular dark-field) electron microscopy with EDX (energy-dispersive X-ray) analysis and CO pulse chemisorption and FTIR (Fourier transform infrared spectroscopy) of adsorbed CO. The amount and the ease with which Pd beta-hydride was formed was found to be dependent on the metal surface area, the presence of titania overlayers, and the Pd surface roughness/defect concentration.

Teschner, D., U. Wild, et al. (2005). "Surface State and Composition of a Disperse Pd Catalyst after Its Exposure to Ethylene." The Journal of Physical Chemistry B 109(43): 20516-20521.
        Pd black was exposed to ethylene alone or in its mixture with hydrogen at 300 and 573 K. The samples were investigated by X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). Room temperature introduction of C2H4 (also in the presence of H2) induced a binding-energy (BE) shift in the Pd 3d doublet and changed its full width at half-maximum (fwhm). The UPS features indicate shifting of electrons from the Pd d-band to PdH, PdC, and even PdOH species. Vinylidene (BE 284.1 eV) may be the most abundant individual surface species on disperse Pd black, along with carbon in various stages of polymerization: disordered C (BE 284 eV), graphite (284.6 eV), and ethylene polymer (286 eV), and also some atomic C (BE 283.5 eV). Introduction of H2 followed by ethylene brought about stronger changes in the state of Pd than exposure in the reverse sequence. This may indicate that the presence of some surface C may hinder the decomposition of bulk PdH. Formation of Pd hydride was blocked when ethylene was introduced prior to H2. The C 1s intensity increased, the low-binding-energy C components disappeared, and graphitic carbon (BE 284.6 eV) prevailed after ethylene treatment at 573 K. The loss of the Pd surface state and PdH signal were observed in the corresponding valence band and UPS spectra. Hydrogen treatment at 540 K was not able to decrease the concentration of surface carbon and re-establish the near-surface H-rich state. UPS showed overlayer-type C in these samples. The interaction of Pd with components from the feed gas modified its electronic structure that is consistent with lattice strain induced by dissolution of carbon and hydrogen into Pd, as indicated by the d-band shift and the dilution of the electron density at EF.

Yamauchi, M., R. Ikeda, et al. (2008). "Nanosize Effects on Hydrogen Storage in Palladium." The Journal of Physical Chemistry C 112(9): 3294-3299.
        The size dependencies of the hydrogen-storage properties in polymer-coated Pd nanoparticles with diameters of 2.6 +- 0.4 and 7.0 +- 0.9 nm were investigated by a measurement of hydrogen pressure-composition isotherms. Their storage capacities per constituent Pd atom in the particles decreased with decreasing particle size, whereas the hydrogen concentrations in the two kinds of nanoparticles were almost the same and 1.2 times as much, respectively, as that in bulk palladium after counting zero hydrogen occupancy on the atoms in the first surface layer of the particles. Furthermore, apparent changes in hydrogen absorption behavior with decreasing particle size were observed, that is, a narrowing of the two-phase regions of solid-solution and hydride phases, the lowering of the equilibrium hydrogen pressure, and a decrease in the critical temperature of the two-phase state. By analyzing the isotherms, we quantitatively determined the heat of formation (DeltaHalphabeta) and the entropy change (DeltaSalphabeta) in the hydride formation of the nanoparticle. DeltaHalphabeta and DeltaSalphabeta for the 2.6 +- 0.4 nm diameter Pd nanoparticle were 34.6 +- 0.61 kJ(H2 mol)-1 and 83.1 +- 1.8 J(H2 mol)-1K-1, whereas for the 7.0 +- 0.9 nm diameter Pd nanoparticles the values were 31.0 +- 1.8 kJ(H2 mol)-1 and 67.3 +- 5.1 J(H2 mol)-1K-1, respectively. These quantities gave us a prospective picture of hydrogen absorption in Pd nanoparticles and the peculiarities in the formation of a single nanometer-sized hydride.
赞一下(4人) 回复此楼
快乐但不成功的小草
3楼2010-01-17 20:12:26
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

xuwangri

木虫 (正式写手)

钯电化学储氢如何?

引用回帖:
Originally posted by yjfeng2000 at 2010-1-17 20:12:
钯本身是一个很好的储氢材料,一般合成钯都是通过氢气还原的方法,所以这个钯催化剂本身就有PdHx相存在.建议你看看下面的参考文献.
Flanagan, T. B. and S. Luo (2006). "Thermodynamics of Hydrogen Solutio ...

楼上,对钯储氢很了解啊. 兄弟想了解下钯电化学储氢的研究进展,谢谢!有文献吗?哈哈,偷懒了.
赞一下 回复此楼
4楼2010-01-18 08:38:26
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

yjfeng2000

木虫 (著名写手)
我不做电化学储氢，这是因为准备一个合作项目想用钯作作为甲醇氧化和氧气还原催化剂时，我准备的资料.
赞一下 回复此楼
快乐但不成功的小草
5楼2010-01-18 15:16:19
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 伊珑静 的主题更新
51/1返回列表
普通表情 龙 兔 虎 猫 高级回复 (可上传附件)
信息提示
关闭
请填处理意见
关闭