共查询到20条相似文献,搜索用时 15 毫秒
1.
Qiuman Zhou Ke Yu Zhanchang Pan Zhaojie Huang Yanbin Xu Guanghui Hu Shoukun Wu Chun Chen Luhua Lin Yingsheng Lin 《International Journal of Hydrogen Energy》2018,43(50):22519-22528
A novel Ni-doped TiN modified N-doped CNTs hybrid nanotubes (N-CNTs@TiNiN) is constructed and serves as hybrid support for the platinum (Pt) catalyst. We prepare the N-CNTs@TiNiN support by a solvothermal process followed by a nitriding process. It is used as anodic catalyst support to test methanol electrooxidation. By contrast, the current density of Pt/N-CNTs (0.34 A mgpt?1) is nearly 1.31 times more than Pt/CNTs (0.26 A mgpt?1) while Pt/TiNiN (0.56 A mgpt?1) is almost 1.33 times as much as Pt/TiN (0.42 A mgpt?1). What's more, among all the catalysts investigated in this work, the novel Pt/N-CNTs@TiNiN (0.86 A mgpt?1) shows the highest reactivity for methanol oxidation, which is also much more active and durable than the commercial JM Pt/C catalyst, showing only slight activity variation even after 12 000 potential cycles. The synthetic Pt/N-CNTs@TiNiN catalyst is researched on its electrocatalytic performance toward methanol electrooxidation and the high activity and durability might be mainly attributed to the electron transfer due to the synergistic effect of the robust TiNiN NPs and N-CNTs by inducing both co-catalytic and electronic effects. 相似文献
2.
Gen Liu Zhanchang Pan Bo Zhang Jun Xiao Guowei Xia Qixiang Zhao Shikun Shi Guanghui Hu Chumin Xiao Zhigang Wei Yanbin Xu 《International Journal of Hydrogen Energy》2017,42(17):12467-12476
The application of direct methanol fuel cells (DMFCs) is hampered by not only low activity but also poor stability and poor CO tolerance by the Pt catalyst. Herein, a novel titanium nitride coated multi-walled carbon nanotubes (CNTs@TiN) hybrid support was successfully synthesized by a facile solvothermal process followed by a nitriding process, and this hybrid support was used as Pt support for the oxidation of methanol. The structure, morphology and composition of the synthesized CNTs@TiN exhibits a uniform particle perfect coating with high purity and interpenetrating network structure. Notably, Pt/CNTs@TiN also showed excellent stability, experiencing only a slight performance loss after 5000 potential cycles. The onset potential (0.34 V) of CO oxidation on Pt/CNTs@TiN is obviously more negative than that on the Pt/TiN (0.38 V) and Pt/CNTs (0.48 V) in the first forward scan. In the Pt 4f XPS spectra, plentiful Pt atoms existed as Pt(II) in the Pt/CNTs and Pt/TiN catalysts, while a relatively smaller amount of Pt(II) was observed in the Pt/CNTs@TiN catalyst. The synthetic Pt/CNTs@TiN catalyst was studied with respect to its electrocatalytic activity and durability and CO tolerance toward methanol oxidation might be mainly attributed to the strongly coupled Pt–TiN and the fast electron-transport network structure. This work may provide more insight into developing novel catalyst supports of various transition metal nitrides coated CNTs for DMFCs with high activity and good durability and excellent CO tolerance. 相似文献
3.
《International Journal of Hydrogen Energy》2020,45(58):33634-33640
The research for electrocatalyst with high electroactivity and great CO-resistance ability for direct methanol fuel cells (DMFCs) is still a huge challenge. In this report, we develop Boron, Nitrogen co-doped carbon nanotubes (BNC NTs) as a support for Pt. Owing to the doping of boron, the catalyst not only provides extremely active sites for methanol oxidation reactions (MOR) but also protects Pt nanoparticles from agglutinating, performing superior electroactivity and excellent ability to anti CO poisoning. The X-ray photoelectron spectroscopy (XPS) results demonstrate the strong electron effect between Pt and B. Notably, the Pt/BNC NTs catalyst exhibits higher catalytic activity towards MOR and more superior durability in comparison with Pt/NC NTs and commercial JM Pt/C catalyst. The accelerated durability test (ADT) illustrates that Pt/BNC NTs catalyst can improve the issue of electrochemical surface area (ECSA) conservation, with only 30% diminish in comparison with the initial ECSA after 5000 cycles. The experiment result demonstrate that boron doping is the key step to improve the catalytic activities and CO-resistance ability due to the combination effects, involving firm B–C and N–C bonds, the stronger electron transfer in the nanotube structure among Pt, B and N, the stronger adsorption intensity of oxygen species from doped B. 相似文献
4.
《International Journal of Hydrogen Energy》2019,44(13):6886-6895
The disadvantages of high cost, easy poisoning and insufficient durability hinder platinum (Pt) application in direct methanol fuel cells. In this study, a hybrid of reduced graphene oxide/carbon nanotubes-supported hollow copper spheres (Cu/rGO@CNTs) is prepared by a one-step electrodeposition method. Then, the internal and external surfaces of hollow Cu spheres are coated with Pt skims to obtain a hollow bimetallic electrocatalyst (Pt/Cu/rGO@CNTs) through a simple galvanic replacement reaction by immersing Cu/rGO@CNTs in a chloroplatinic acid (H2PtCl6) solution. The three dimensional rGO@CNTs network structure benefit mass transport and electron transfer. Pt skims expose abundant active sites for electrocatalytic methanol oxidation reactions (MORs). Cu cores synergize Pt skims to enhance anti-poison ability. As a result, Pt/Cu/rGO@CNTs shows an excellent electrocatalytic activity for MORs with a robust tolerance of catalyst poisoning. 相似文献
5.
Titanium carbide (TiC) nanoparticles supported Pt catalyst for methanol electrooxidation is investigated for the first time. The resultant TiC/Pt catalysts are prepared by using a simple electrodeposition to load Pt nanoparticles on TiC nanocomposite. The electrodes are characterized by scanning electron microscopy and cyclic voltammetry. It is found that the TiC/Pt catalysts help alleviate the CO poisoning effect for methanol electrooxidation with a higher ratio of the forward anodic peak current (If) to the reverse anodic peak current (Ib). The improvement in the catalytic performance is attributed to the fact that TiC ameliorates the tolerance to CO adsorption on Pt nanoparticles. One possible mechanism to improve the CO tolerance of Pt taking TiC as supporting material in methanol electrooxidation is also proposed. The results suggest that TiC could be practical supporting materials to prepare electrocatalysts that are suitable for the methanol electrooxidation applications. 相似文献
6.
Hai Zhu Juntao Wang Xiaoling Liu Xiaoming Zhu 《International Journal of Hydrogen Energy》2017,42(16):11206-11214
Three-dimensional porous graphene (3D-G) is prepared by template-assembly method and employed as catalyst support for Ni nanoparticles for methanol electrooxidation. Morphology characterization confirm that Ni nanoparticles with sizes around 20 nm are uniformly scattered on the pore wall surface of the three-dimensional graphene without apparent agglomeration. Electrochemical measurements indicate that the Ni/3D-G processes higher electrocatalytic activity for methanol oxidation reaction than that of the Ni nanoparticles supported on two-dimensional graphene (Ni/2D-G) and Ni nanoparticles without graphene. The peak current density on Ni/3D-G is 64.6 mA cm?2, which is 1.5 times higher than that on Ni/2D-G. The remarkable electrocatalytic performance of the Ni/3D-G catalyst are mainly derived from the 3D graphene. As a carrier for methanol oxidation, the 3D-G with abundant pore architecture not only hinder the agglomeration of Ni particles that is beneficial to accelerating the efficient charge transport through the whole catalyst, but also offer readily accessible channels for the diffusion of CH3OH to the active sites of catalyst surface. 相似文献
7.
Testing of carbon supported Pd-Pt electrocatalysts for methanol electrooxidation in direct methanol fuel cells 总被引:1,自引:0,他引:1
Francisco Alcaide Garbiñe ÁlvarezPere L. Cabot Hans-Jürgen GrandeOscar Miguel Amaia Querejeta 《International Journal of Hydrogen Energy》2011,36(7):4432-4439
In the present work, a detailed characterization of the electrochemical behavior of carbon supported Pd-Pt electrocatalysts toward CO and methanol electrooxidation in direct methanol fuel cells is reported. Technical electrodes containing an ionomer in their catalyst layer were prepared for this purpose. CO and methanol electrooxidation reactions were used as test reactions to compare the electrocatalytic behavior of bimetallic supported nanoparticles in acidic liquid electrolyte and in solid polymer electrolyte (real fuel cell operating conditions). Experimental results in both environments are consistent and show that the electrochemical behavior of carbon supported Pd-Pt depends on their composition, giving the best performance in direct methanol single fuel cell with a Pd:Pt atomic ratio of 25:75 in the catalyst. 相似文献
8.
Guangwen Feng Zhanchang Pan Yanbin Xu Haijiao Chen Guowei Xia Yafeng Zhang Shikun Shi Xihui Deng 《International Journal of Hydrogen Energy》2018,43(36):17064-17068
In this study, mesoporous titanium cobalt nitride nanorods (Ti0.9Co0.1N NRs) hybrid as non-carbon platinum supports is successfully prepared by a solvothermal process and subsequent nitridation process. The highly porous materials can provide abundant binding sites for growing well-dispersed Pt. The X-ray photoelectron spectroscopy results indicate that the cobalt element doping promoted the interaction of platinum and support. Notable, the peak current density of Pt/Ti0.9Co0.1N NRs catalyst is 0.85 A mgpt?1, which 3.4-fold of Pt/C catalyst. What's more, the onset potential (0.34 V) of CO oxidation on Pt/Ti0.9Co0.1N NRs is lower than on the Pt/C (0.47 V) and Pt/TiN NRs (0.37 V). The results confirmed the mesoporous Pt/Ti0.9Co0.1N NRs catalyst unfolds a much enhanced catalytic activity and CO tolerance for methanol oxidation. The exceptional electrocatalytic properties are achieved for the Pt/Ti0.9Co0.1N NRs catalysts due to its unique porous structure and the electronic effect of robust Ti0.9Co0.1N NRs introduced by the cobalt element doping. 相似文献
9.
Fathy M.B. Hassan Shanmugam Venkatachalam Mitsuhiro Kanakubo Takeo Ebina 《Journal of power sources》2010,195(18):5889-615
Titania nanotubes (TiNTs) were prepared by electrochemical anodization and were used as a support for depositing Pt. After annealing the TiNTs changed to crystalline anatase phase and were doped with carbon. The TiNTs/Pt/C was tested as electrode for electrochemical catalysis of methanol oxidation. The composite catalyst activities were measured by cyclic voltammetry in 1 M CH3OH + 1 M H2SO4. The results demonstrated that TiNTs/Pt/C can greatly enhance the catalytic activity of methanol oxidation. The CO stripping led to the increase in the current peak of methanol oxidation due to activating the catalyst surface by point defect formation. Moreover, the higher ratio of the forward anodic peak current to the reverse anodic peak current indicates more effective removal of the poisonous species. 相似文献
10.
Esteban A. FranceschiniGabriel A. Planes Federico J. WilliamsGalo J.A.A. Soler-Illia Horacio R. Corti 《Journal of power sources》2011,196(4):1723-1729
Mesoporous Pt and Pt/Ru catalysts with 2D-hexagonal mesostructure were synthesized using a triblock poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) copolymer (Pluronic F127®) template, on a gold support. Large electrochemical surface areas were observed for the catalysts prepared at high overpotentials. Compared to the Pt catalyst, the Pt/Ru alloy containing 3 at% of Ru exhibited lower onset potential and more than three times the limit mass activity for methanol oxidation. This behavior is assigned to the larger pore size of the mesoporous Pt and Pt/Ru catalysts obtained with this template that seems to improve the methanol accessibility to the active sites compared to those obtained using lyotropic liquid crystals. 相似文献
11.
Rezgar AhmadiMohammad K. Amini 《International Journal of Hydrogen Energy》2011,36(12):7275-7283
Pt nanoparticles supported on carbon nanotubes (Pt/CNTs) have been synthesized from sulfur-modified CNTs impregnated with H2PtCl6 as Pt precursor. The dispersion and size of Pt nanoparticles in the synthesized Pt/CNT nanocomposites are remarkably affected by the amount of sulfur modifier (S/CNT ratio). The results of X-ray diffraction and transmission electron microscopy indicate that an S/CNT ratio of 0.3 affords well dispersed Pt nanoparticles on CNTs with an average particle size of less than 3 nm and a narrow size distribution. Among different catalysts, the Pt/CNT nanocomposite synthesized at S/CNT ratio of 0.3 showed highest electrochemically active surface area (88.4 m2 g−1) and highest catalytic activity for methanol oxidation reaction. The mass-normalized methanol oxidation peak current observed for this catalyst (862.8 A g−1) was ∼ 6.5 folds of that for Pt deposited on pristine CNTs (133.2 A g−1) and ∼ 2.3 folds of a commercial Pt/C (381.2 A g−1). The results clearly demonstrate the effectiveness of a relatively simple route for preparation of sulfur-modified CNTs as a precursor for the synthesis of Pt/CNTs, without the need for tedious pretreatment procedures to modify CNTs or complex equipments to achieve high dispersion of Pt nanoparticles on the support. 相似文献
12.
Huiru Zhao Yi Wang Qinghu Tang Li Wang Hui Zhang Can Quan Tao Qi 《International Journal of Hydrogen Energy》2014
Pt catalysts supported on titanium suboxide (Ti4O7), commercial TiO2 and carbon black were prepared by a borohydride reduction method, respectively, and used as electrocatalysts for direct formic acid fuel cells (DFAFCs). Transmission electron microscopy (TEM) images show that Pt nanoparticles have a poorer dispersion on Ti4O7 compared to that on TiO2 and carbon black due to the hydrophobicity and high density of Ti4O7. Nevertheless, according to cyclic voltammetry (CV) and chronoamperometry (CA) results, it is found that the Pt/Ti4O7 catalyst possesses better catalytic activity and stability. Besides the high electrical conductivity, it is suggested from X-ray photoelectron spectroscopy (XPS) analyses that the higher content of metallic Pt caused by the Ti4O7 support material also contributes to the better catalytic performance of Pt/Ti4O7. 相似文献
13.
《International Journal of Hydrogen Energy》2019,44(3):1671-1685
Here, novel polyvinyl alcohol (PVA) nanofibers with incorporated CuO and Co3O4 nanoparticles (PVA-CuOCo3O4) were synthesized through a conventional single-nozzle electrospinning technique and characterized by atomic force microscopy (AFM), energy dispersive X-ray analysis (EDX), fourier-transform infrared spectroscopy (FT-IR), elemental analysis, transmission electron microscopy (TEM), differential thermal analysis (DTA), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Novel Pt/polyvinyl alcohol-CuOCo3O4/chitosan (Pt/PVA-CuOCo3O4/CH) catalyst was successfully prepared. EDX, TEM, and FT-IR spectroscopy techniques were used to characterize the prepared catalysts. The electrocatalytic activity of Pt/PVA-CuOCo3O4/CH catalyst was investigated for methanol electrooxidation through cyclic voltammetry, chronoamperometry, CO stripping voltammetry, and electrochemical impedance spectroscopy techniques. The effects of some experimental factors for methanol electrooxidation were studied on the prepared catalysts and the optimum conditions were determined. Pt/PVA-CuOCo3O4/CH catalyst had extraordinary electrocatalytic activity for methanol electrooxidation. It exhibited better stability, higher electrochemically active surface area, and better antipoisoning effect than Pt/PVA-CuOCo3O4 and Pt/PVA/CH catalysts indicating that Pt/PVA-CuOCo3O4/CH could be a promising catalyst for direct methanol fuel cell (DMFC) applications. A real DMFC was designed, assembled and tested with Pt/PVA-CuOCo3O4/CH as anodic catalyst. 相似文献
14.
Platinum (Pt) and platinum–ruthenium (PtRu) nanoparticles supported on Vulcan XC-72 carbon and single-wall carbon nanotubes (SWCNT) are prepared by a microwave-assisted polyol process. The catalysts are characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The PtRu nanoparticles, which are uniformly dispersed on carbon, have diameters of 2–6 nm. All the PtRu/C catalysts display the characteristic diffraction peaks of a face centred cubic Pt structure, excepting that the 2θ values are shifted to slightly higher values. The results from XPS analysis reveal that the catalysts contain mostly Pt(0) and Ru(0), with traces of Pt(II), Pt(IV) and Ru(IV). The electrooxidation of methanol is studied by cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. Both PtRu/C catalysts have high and more durable electrocatalytic activities for methanol oxidation than a comparative Pt/C catalyst. Preliminary data from a single direct methanol fuel cell using the SWCNT supported PtRu alloy as the anode catalyst delivers high power density. 相似文献
15.
Jian-Qiang Zeng Sheng-Nan SunJing-Ping Zhong Xiao-Feng LiRui-Xiang Wang Li-Na WuLi Wang You-Jun Fan 《International Journal of Hydrogen Energy》2014
The hydrothermal synthesis of a novel Pd electrocatalyst using copper phthalocyanine-3,4′,4″,4′″-tetrasulfonic acid tetrasodium salt (TSCuPc) functionalized multi-walled carbon nanotubes (MWCNTs) composite as catalyst support for Pd nanoparticles is reported. The prepared nanocomposites were characterized by UV–vis absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. It is found that Pd nanoparticles are uniformly deposited on the surface of TSCuPc-MWCNTs, and their dispersion and electrochemical active surface area (ECSA) are significantly improved. Studies of cyclic voltammetry and chronoamperometry demonstrate that the Pd/TSCuPc-MWCNTs exhibits much higher electrocatalytic activity and stability than the Pd/AO-MWCNTs catalyst for formic acid oxidation. This study implies that the as-prepared Pd/TSCuPc-MWCNTs will be a promising candidate as an anode electrocatalyst in direct formic acid fuel cell (DFAFC). 相似文献
16.
Je-Suk Moon Young-Woo LeeSang-Beom Han Kyung-Won Park 《International Journal of Hydrogen Energy》2014
We demonstrate Pd nanoparticles on well-defined mesoporous tungsten carbide (Pd/meso-WC) for methanol electrooxidation in alkaline solution. The meso-WC exhibits mesoporous structure with ∼8.5 nm in average pore size and ∼47 m2 g−1 in specific surface area. The Pd nanoparticles with size of ∼3.3 nm are highly dispersed on the meso-WC. The electron transfer from W to Pd due to the difference of electronegativity is confirmed by X-ray photoelectron spectroscopy. The improved electrocatalytic activity and stability for methanol electrooxidation of Pd/meso-WC is likely to be mainly attributed to a strong interaction between Pd nanoparticles and mesoporous tungsten carbide structure. 相似文献
17.
One anti-CO-poisoning Pt-WC/C catalyst for methanol electro-oxidation is prepared in this work, through depositing platinum on tungsten carbide support using an intermittent microwave heating (IMH) method. The catalyst presents an improved methanol oxidation performance evidenced by a negative shift in onset potential, and increase of peak current density, compared with a commercial Pt/C one. CO stripping experiments indicate that the adsorbed CO is able to be oxidized and removed from the Pt-WC/C catalyst more easily, attesting the enhanced capability of anti-poisoning to CO-like species. Theoretical calculation further provides evidence that the surface electronic structure in Pt-WC/C and Pt/C catalysts is likely different. WC supports could lead to much stronger negative electronic property, which is beneficial for avoiding CO adsorption on the Pt-WC/C catalyst. In the mean time, the electron donating effect generated by WC supports also promotes the ability to oxidize the adsorbed CO-like species on catalysts. In good agreement with experimental results, the theoretical calculation proves the anti-CO-poisoning nature of the Pt-WC/C catalyst, and well explains the origin of the improvement in the electrochemical catalytic performance for effectively accelerating the oxidation of CO to CO2 in methanol oxidation. 相似文献
18.
《International Journal of Hydrogen Energy》2020,45(16):9795-9802
In this work, a facile Fe- and N-containing porous carbon derived from sewage sludge was prepared and served as the support of Pt nanoparticles for the electrooxidation of methanol. Both the sludge-derived carbon (denoted as SC) and the resultant Pt/SC catalyst was physically characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The electrocatalytic performance for methanol oxidation reaction (MOR) of the Pt/SC was examined by cyclic voltammetry (CV) and chronoamperometric method. The results showed that the Pt/SC possessed slightly larger Pt particle size (5.5 nm) and lower electrochemical active surface area (ECA) compared to common Pt/C catalyst. However, the mass activity of Pt/SC for MOR was up to 201 mA mg−1, which was much higher than that of Pt/C (93 mA mg−1), indicating the synergistic effect of the sewage sludge-derived carbon with Fe and N species on methanol electrooxidation. Furthermore, Pt/SC showed enhanced durability towards MOR compared to common Pt/C, implying its potential for using in direct methanol fuel cell (DMFC) for energy conversion, which also demonstrated a promising solution for the utilization of sewage sludge resources. 相似文献
19.
Performance of Pt/C catalysts prepared by microwave-assisted polyol process for methanol electrooxidation 总被引:1,自引:0,他引:1
Pt nanoparticles catalysts supported on the Vulcan XC-72 carbon black with different mean sizes have been synthesized by microwave-assisted polyol process and characterized by energy dispersive analysis of X-ray (EDAX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results of physical examinations show that Pt nanoparticles have a narrow size distribution and are highly dispersed on the surface of carbon support, and Pt loading in Pt/C catalyst is the similar with the theoretical value. The results of cyclic voltammetry and chronoamperometry demonstrate that the Pt/C catalyst prepared by microwave-assisted polyol process at the pH value of about 12 exhibits the highest catalytic activity for methanol electrooxidation. The activity of Pt/C catalyst is also related to the microwave heating time, and the optimal heating time is 40 s in this work. 相似文献
20.
《International Journal of Hydrogen Energy》2022,47(55):23360-23372
Liquid-fueled direct methanol fuel cell (DMFC) is highly promising for low-carbon transportation, but is hindered by high cost and short lifespan of conventional Pt-based electrocatalysts. Herein, we propose a new Pt-free catalyst strategy to exploit high-performing and stable electrocatalyst of DMFC, achieving enhanced electrocatalytic activity and high stability for methanol oxidation reaction (MOR) in alkaline media. A new Pt-free anode catalysts consisting of titanium/reduced-titanium dioxide nanotubes/nickel/cerium dioxide (Ti/r-TiO2NTs/Ni/CeO2) nanosupport and uniformly-dispersed Pd dendrites is successfully prepared by a facile three-step electrodeposition route without applying any template or surfactant. Noticeably, the as-prepared Ti/r-TiO2NTs/Ni/CeO2–Pd as an anode electrode exhibits superior activity than commercial Pd/C and other electrodes. The obtained large mass activity for Ti/r-TiO2NTs/Ni/CeO2–Pd electrode is 1752 mA mgPd?1 for MOR. After successive CV tests of 1000 cycles, Ti/r-TiO2NTs/Ni/CeO2–Pd electrode still retained 88.9% of its initial current. The superior performance of Ti/r-TiO2NTs/Ni/CeO2–Pd attributes to the large surface area and excellent conductivity, as well as the synergistic effects among nanosupport and Pd dendrites. Therefore, this study will open a new door for high-performance fuel cell applications. 相似文献