Methanol Electrooxidation In Alkaline Media Research Articles

Synthesis and structural characterization of a ternary palladium–ruthenium–tin nanoalloy supported on graphene nanosheets for methanol electrooxidation in alkaline medium

A graphene-supported ternary Pd–Ru–Sn nanoalloy with a face centered cubic structure has been synthesized by a microwave-assisted polyol reduction method and investigated for electrooxidation of methanol in 1 M KOH at 25 °C. The electrocatalytic activity of the novel ternary alloy electrode is more than 2 times higher than that of the Pd/GNS (base) electrode. It is observed that the percentage increase in catalytic activity of the ternary alloy electrode in comparison with the base electrode increases with the electrolysis time during the chronoamperometry study.

Preparation of well-distributed Pt–Ni nanoparticles on/into TiO2NTs by pulse electrodeposition for methanol photoelectro-oxidation

Abstract Evenly dispersed Pt–Ni nanoparticles were loaded on TiO 2 nanotube arrays (TiO 2 NTs) via pulse electrodeposition method and subsequently characterized by FESEM, EDX and XRD. The electrochemical studies showed that the catalytic activities of Pt–Ni/TiO 2 NTs are better than that of Pt/TiO 2 NTs for methanol electro-oxidation in alkaline media both in the dark and under illumination. In addition, due to the interaction of electro-catalysis and photo-catalysis, the catalytic activities of TiO 2 NTs-based catalysts were improved largely under illumination. Base on the results obtained in this work, Pt–Ni/TiO 2 NTs may be used to develop a base for photo assist direct methanol fuel cell.

Enhanced methanol electro-oxidation activity of PtNi alloy nanoparticles on the large surface area porous carbon

A kind of porous carbon (AC-K) with high surface area 2972 m2/g was obtained by treating activated carbon (AC) with KOH, which was investigated as the support for direct methanol fuel cell. PtNi nanoparticles were synthesized by chemical reduction with hydrazine using PVP as a stabilizer and deposited onto AC-K to produce PtNi/AC-K catalyst. Pt/AC-K and Pt/AC catalysts were also prepared under similar condition with the same nominal metal loading 20 wt.%. Their structures, morphologies, and electrocatalytic properties were investigated and compared. X-ray diffraction shows the alloy formation for Pt and Ni for PtNi/AC-K catalyst. Transmission electron microscopy reveals Pt/AC-K has a lower degree of agglomeration than Pt/AC. Moreover, PtNi/AC-K consists of nanoparticles with the lowest average particle size and best dispersion among the three catalysts. Nitrogen sorption at 77 K indicates that the potassium hydroxide activation can remarkably increase specific surface area and micropore volumes, which may be favorable for anchoring metal nanoparticle. Pt alloying with Ni may also contribute to the smaller particle size and better dispersion. Consequently, the activities of methanol oxidation investigated by cyclic voltammograms follow the order of PtNi/AC-K > Pt/AC-K > Pt/AC. Hence, the porous carbon AC-K and the corresponding catalyst PtNi/AC-K show great potential as support and less expensive electrocatalyst respectively for methanol electrooxidation in alkaline media in direct methanol fuel cells.

Simultaneous reduction–etching route to Pt/ZnSnO3hollow polyhedral architectures for methanol electrooxidation in alkaline media with superior performance

In this communication, a simultaneous reduction-etching route is exploited to fabricate Pt/ZnSnO(3) hollow polyhedra. The hollow ZnSnO(3) polyhedron is found to act as a novel and efficient support of Pt-based catalyst for methanol electrooxidation in alkaline media.

Microwave-assisted, environmentally friendly, one-pot preparation of Pd nanoparticles/graphene nanocomposites and their application in electrocatalytic oxidation of methanol

In this communication, we demonstrate for the first time that Pd nanoparticles/graphene nanocomposites (PdNPs–G) can be rapidly synthesized through a microwave-assisted, environmentally friendly, one-pot method with the use of tannic acid (TA) as a reducing agent. It is suggested that the loading amount and sizes of PdNPs on a G sheet can be controlled by the ratio of raw materials and microwave irradiation time. It is also found that the electrocatalytic activity and stability of the resultant PdNPs–G nanocomposites are much better than that of commercial Pd/C catalysts towards methanol electrooxidation in alkaline media.

TiO 2 nanotube-supported amorphous Ni–B electrode for electrocatalytic oxidation of methanol

Amorphous Ni–B/TiO 2 electrodes were successfully prepared by electroless plating. Highly ordered TiO 2 nanotube arrays fabricated by anodic oxidation were employed as substrate and loaded with Ni–B alloy by electroless plating. The phase formation, microstructures and catalytic activity of electrodes were investigated by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and electrochemistry analyzer, respectively. The results show that Ni–B/TiO 2 electrodes with an average particle size of 200 nm present a typical amorphous structure of Ni and B, and have high catalytic activity for methanol electrooxidation in alkaline medium. The peak current density in cyclic voltammetry (CV) curves reaches 360 mA cm −2 in the solution with 0.5 mol L −1 methanol, much higher than that of Ni–B/Ti electrode. With the methanol concentration increasing to 1.5 mol L −1, the peak current density increases to 488 mA cm −2, after which it remains almost constant. The Ni–B/TiO 2 electrodes are relatively stable according to catalytic lifetime test; the peak current density remains 72.1% of the original value after 1300 times cycles. The amorphous Ni–B/TiO 2 electrode should be a promising candidate for direct methanol fuel cell.

A highly active PtNi/C electrocatalyst for methanol electro-oxidation in alkaline media

A carbon supported PtNi/C electrocatalyst synthesized via a polyol process was characterized by XRD, TEM and voltammetry techniques. The XRD analysis showed a decreased lattice constant of Pt for the PtNi/C catalyst compared with the Pt/C. indicating partial PtNi alloy formed. The PtNi/C exhibited enhanced mass activity towards methanol oxidation reaction as well as decreased CO stripping currents in alkaline media compared with the Pt/C. Density functional theory studies revealed the electronic structure modification of Pt by Ni atoms and weakened CO adsorption energy on the Pt(3)Ni than on the Pt(4) clusters, which may account for the increased MOR activity. Crown Copyright (C) 2010 Published by Elsevier By. All rights reserved.

MnO 2 modified multi-walled carbon nanotubes supported Pd nanoparticles for methanol electro-oxidation in alkaline media

A novel method to prepare MnO 2 modified multi-walled carbon nanotubes (MnO 2/MWCNTs) supported Pd (Pd-MnO 2/MWCNTs) electrocatalyst is reported. The morphology, component and crystallinity of the catalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The activity of Pd-MnO 2/MWCNTs was tested using methanol electro-oxidation in alkaline media. The results showed that the Pd-MnO 2/MWCNTs exhibited higher electrocatalytic activity and stability than Pd/MWCNTs and Pd/Vulcan (Pd/commercial Vulcan XC-72 carbon black).

Electrocatalysis of gold nanoparticles/layered double hydroxides nanocomposites toward methanol electro-oxidation in alkaline medium

A nanocomposite based on layered double hydroxides (LDHs) and gold nanoparticles (AuNPs) was prepared via hydrothermal treatment followed by a reduction procedure. The AuNPs were obtained in Mg–Al LDHs, and they maintained good stability. The electrocatalytic activities of AuNPs/LDH-modified glassy carbon electrodes for methanol oxidation in alkaline medium were investigated in detail. Under the same conditions, the modified electrode exhibited higher electrocatalytic activity than both the pure AuNPs-modified electrode and LDH-modified electrode. The role of the AuNPs and LDHs in this composite system was explored by cyclic voltammetry and chronoamperometry, respectively. Further studies demonstrated that the promoting effect of LDHs could be due to its strong adsorption and partly to the discharge of OH − during methanol oxidation. This work indicates that LDHs is expected to be a good supporting material in the development of methanol anode catalysts.

Electrochemical fabrication of novel platinum-poly(5-nitroindole) composite catalyst and its application for methanol oxidation in alkaline medium

A novel composite catalyst, Pt nanoparticles supported on poly(5-nitroindole) (Pt/PNI), has been successfully prepared by the electrochemical method and used for the electrooxidation of methanol in alkaline media. As-prepared Pt/PNI was characterized by SEM, EDX and electrochemical methods. The results of the catalytic activity for methanol oxidation showed that Pt/PNI had higher catalytic activity and stronger poisoning-tolerance than Pt/Pt, Pt/GC and the common Pt electrode. The effects of different parameters related to the methanol oxidation reaction kinetics, such as Pt loading, mass of PNI film, concentration of methanol and KOH, potential scan rate, have also been investigated. The present study showed a promising choice of Pt/PNI as composite catalyst for methanol electrooxidation in alkaline medium.

Pt-rich shell coated Ni nanoparticles as catalysts for methanol electro-oxidation in alkaline media

National Science Foundation of China [20673089]; key scientific project of Fujian Province of China [2005HZ01-3]; National Fundamental Research (973) Program of China [2009CB939804]

High Utilization AuPt Nanoparticles Supported on MWCNTS for Methanol Electro-oxidation in Alkaline Medium

High Utilization AuPt Nanoparticles Supported on MWCNTS for Methanol Electro-oxidation in Alkaline Medium

Physical and electrochemical characterizations of nanostructured Pd/C and PdNi/C catalysts for methanol oxidation

Pd and PdNi nanoparticles supported on Vulcan XC-72 carbon were prepared by a chemical reduction with formic acid process. The catalysts were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry, and chronoamperometry. The results showed that the Pd and PdNi nanoparticles, which were uniformly dispersed on carbon, were 2–10 nm in diameters. The PdNi/C catalyst has higher electrocatalytic activity for methanol oxidation in alkaline media than a comparative Pd/C catalyst and shows great potential as less expensive electrocatalyst for methanol electrooxidation in alkaline media in direct methanol fuel cells.

Potassium ferrate(VI) and decomposed K 2FeO 4 assisted methanol electro-oxidation in alkaline media

The cyclic voltammograms (CVs) and current-time curves of methanol electro-oxidation, assisted by K 2FeO 4, decomposed K 2FeO 4 and Fe(NO 3) 3 added in strong alkaline solution, were investigated on a Pt electrode. The results show that Fe(NO 3) 3 and K 2FeO 4, especially decomposed K 2FeO 4, can promote the activity and poisoning tolerance of a Pt electrocatalyst for methanol oxidation in alkaline solution. We propose that iron(III)-containing compounds such as Fe(OH) 3 and FeOOH in a strong alkaline solution tend to encourage the formation of OH adsorption (OH ads) species, which are necessary for the promotion of the CO-like intermediates of oxidation on the Pt electrode.