Mn-Mo-O Catalysts for Methanol Oxidation. II. Oxidation of Methanol

1992 ◽  
Vol 57 (12) ◽  
pp. 2539-2547 ◽  
Author(s):  
Krasimir Ivanov ◽  
Penka Litcheva ◽  
Dimitar Klissurski
Keyword(s):  
Catalytic Activity ◽  
Methanol Oxidation ◽  
Catalytic Properties ◽  
Effect Of Temperature ◽  
Second Step ◽  
Gas Mixture ◽  
Direct Oxidation ◽  
Step Process ◽  
Oxidation Of Methanol ◽  
Small Excess

The catalytic properties of MnMoO4-based catalysts toward methanol oxidation are investigated. The effect of temperature, flow rate and gas mixture composition on the catalytic activity is established. The highest activity and selectivity (comparable with those of industrial catalysts) of the samples obtained by precipitation in the presence of a small excess of MoO3 was found. The oxidation of methanol on MnMoO4-based catalyst is proposed to be a two-step process. The first step includes methanol interaction with Mo(VI) and reduction of Mo(VI) to Mo(V) (Mo(IV)). The second step consists in direct oxidation of the reduced molybdenum by oxygen from the alcohol-air mixture.

scholarly journals Effects of the Interfacial Structure on the Methanol Oxidation on Platinum Single Crystal Electrodes

Surfaces ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 177-192 ◽  
Author(s):  
Mohammad Kamyabi ◽  
Ricardo Martínez-Hincapié ◽  
Juan Feliu ◽  
Enrique Herrero
Keyword(s):  
Single Crystal ◽  
Methanol Oxidation ◽  
Interfacial Structure ◽  
Direct Oxidation ◽  
Adsorbed Species ◽  
Oxidation Of Methanol ◽  
Methanol Solutions ◽  
Platinum Single Crystal ◽  
The Right

Methanol oxidation has been studied on low index platinum single crystal electrodes using methanol solutions with different pH (1–5) in the absence of specific adsorption. The goal is to determine the role of the interfacial structure in the reaction. The comparison between the voltammetric profiles obtained in the presence and absence of methanol indicates that methanol oxidation is only taking place when the surface is partially covered by adsorbed OH. Thus, on the Pt(111) electrode, the onset for the direct oxidation of methanol and the adsorption of OH coincide. In this case, the adsorbed OH species are not a mere spectator, because the obtained results for the reaction order for methanol and the proton concentrations indicate that OH adsorbed species are involved in the reaction mechanism. On the other hand, the dehydrogenation step to yield adsorbed CO on the Pt(100) surface coincides with the onset of OH adsorption on this electrode. It is proposed that adsorbed OH collaborates in the dehydrogenation step during methanol oxidation, facilitating either the adsorption of the methanol in the right configuration or the cleavage of the C—H bond.

Optimization of Mesh-Based Anodes for Direct Methanol Fuel Cells

2010 ◽  
Vol 7 (3) ◽  
Author(s):  
Raghuram Chetty ◽  
Keith Scott ◽  
Shankhamala Kundu ◽  
Martin Muhler
Keyword(s):  
Thermal Decomposition ◽  
Fuel Cell ◽  
Methanol Oxidation ◽  
Photoelectron Spectroscopy ◽  
Direct Methanol Fuel Cells ◽  
Linear Sweep Voltammetry ◽  
Effect Of Temperature ◽  
X Ray ◽  
Oxidation Of Methanol ◽  
Direct Methanol

Platinum based binary and ternary catalysts were prepared by thermal decomposition onto a titanium mesh and were evaluated for the anodic oxidation of methanol. The binary Pt:Ru catalyst with a composition of 1:1 gave the highest performance for methanol oxidation at 80°C. The effect of temperature and time for thermal decomposition was optimized with respect to methanol oxidation, and the catalysts were characterized by cyclic voltammetry, linear sweep voltammetry, scanning electron microscopy, X-ray diffraction studies, and X-ray photoelectron spectroscopy. The best catalyst was evaluated in a single fuel cell, and the effect of methanol concentration, temperature, and oxygen/air flow was studied. The mesh-based fuel cell, operating at 80°C with 1 mol dm3 methanol, gave maximum power densities of 38 mW cm−2 and 22 mW cm−2 with 1 bar (gauge) oxygen and air, respectively.

Preparation of Nanosized Pt-Au Alloy Catalyst and Its Activity in Methanol Oxidation

2007 ◽  
Vol 7 (11) ◽  
pp. 4073-4076 ◽  
Author(s):  
Ki-Joong Kim ◽  
Yong-Hwa Kim ◽  
Woon-Jo Jeong ◽  
Seung-Won Jeong ◽  
Jong-Che Park ◽  
...  
Keyword(s):  
Particle Size ◽  
Catalytic Activity ◽  
Methanol Oxidation ◽  
Flow Reactor ◽  
Metal Catalyst ◽  
Deposition Method ◽  
Oxidation Activity ◽  
Preparation Methods ◽  
Oxidation Of Methanol ◽  
Alloy Catalyst

The alloy catalyst has been widely used because it will be able to improve the activity and selectivity of the single metal catalyst in a given chemical reaction. In this study, the preparation and characteristics of nanosized Pt and Au particles on alumina and their catalytic activity were described. Nanosized Pt–Au catalysts were prepared by impregnation (IMP) method and deposition (DP) method using alumina or ZnO/Al2O3 as support. The size of Pt and Au particles were observed by transmission electron microscopy (TEM), energy dispersive spectroscope (EDS), and X-ray diffraction (XRD). Catalytic activity for oxidation of methanol was measured using a flow reactor. It could be seen that the Pt particle size and dispersion in the alloy catalysts was rarely influenced by preparation methods and Au particles coated by deposition method were well dispersed. TEM images showed that Au particles were well dispersed in the Pt/Au/ZnO/Al2O3 catalyst of which Au particles was supported by deposition method. The catalytic activity for methanol are given in the order of Pt-Au[IMP]/ZnO/Al2O3 > Pt[IMP]/Au[DP]/ZnO/Al2O3 > Au[DP]/Pt[IMP]/ZnO/Al2O3 > Pt-Au[DP]/ZnO/Al2O3. Therefore, Au particle size was doing not play an important role in increasing the oxidation activity, but the Au particles may promote the methanol oxidation.

Electrocatalytic Oxidation of Methanol on an Pd/Pyy/Niad-atoms Electrode

2013 ◽  
Vol 10 (5) ◽  
Author(s):  
Mohamed Abdelfattah Ibrahim ◽  
Taha Hanfy ◽  
A. A. Al-Ghamdi ◽  
Farid El-Tantawy ◽  
Hossam S. Rageb
Keyword(s):  
Catalytic Activity ◽  
Methanol Oxidation ◽  
Electrocatalytic Oxidation ◽  
Oxidation Of Methanol

In this paper we study the effect of Niad-atoms on the activity of a Pd/Pyy nanocomposite anode, we find that the catalytic activity of an anode towards methanol oxidation increased by threefold in the presence of Niad-atoms.

Catalytic Activity of Porous Pd-Ni Thin Foam towards Electrooxidation of Methanol

2013 ◽  
Vol 16 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Ming Jin ◽  
Houyi Ma
Keyword(s):  
Catalytic Activity ◽  
Methanol Oxidation ◽  
Low Cost ◽  
Nickel Content ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Oxidation Of Methanol ◽  
One Step ◽  
Dynamic Template ◽  
Electrooxidation Of Methanol

Porous Pd-Ni thin foam was fabricated by a rapid one-step electrodeposition process within hydrogen bubble dynamic template and characterized by SEM, EDS, and cyclic voltammetry. Morphology and composition of the foam can be modified significantly by applying different deposition conditions, such as concentration ratio of Pd (II) ions to Ni (II) ions in electrolytic solution and deposition time. Electrocatalytic activities of the foam towards methanol oxidation in alkaline media were investigated, which depend mainly on Pd components and its morphology. Low nickel content can assist Pd further enhance the electrocatalytic performance, particularly the tolerance to intermediates of methanol oxidation, while high nickel content brings adverse effect. The high catalytic activity and the low cost of the Pd-Ni foams enable them to be promising electrocatalysts for the oxidation of methanol in alkaline media.

scholarly journals Formation of Pt–Ag alloy on different silicas – surface properties and catalytic activity in oxidation of methanol

RSC Advances ◽  
2017 ◽  
Vol 7 (16) ◽  
pp. 9534-9544 ◽  
Author(s):  
Joanna Wisniewska ◽  
Maria Ziolek
Keyword(s):  
Catalytic Activity ◽  
Surface Properties ◽  
Methanol Oxidation ◽  
Methyl Formate ◽  
Oxidation Of Methanol

Pt–Ag alloy is formed on silicas if Ag/Pt ≥ 2.5 and gives the highest methyl formate selectivity in methanol oxidation.

Effects of Microwave-synthesizing Parameters on Structure and Electro-catalytic Activity of Pt2Mo/C towards Methanol Oxidation

2010 ◽  
Vol 25 (4) ◽  
pp. 359-364 ◽  
Author(s):  
Xin ZENG ◽  
Xian-Xia YUAN ◽  
Xiao-Yun XIA ◽  
Juan DU ◽  
Hui-Juan ZHANG ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Methanol Oxidation ◽  
Electro Catalytic Activity

Decomposition of hydrogen peroxide on a two-component NiO-CdO catalyst and the effect of ionizing radiation on its catalytic properties

1979 ◽  
Vol 44 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Viliam Múčka
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Nickel Oxide ◽  
Catalytic Properties ◽  
Cadmium Oxide ◽  
Chemisorb Oxygen ◽  
Composition Region ◽  
Chemisorbed Oxygen ◽  
Two Component

The catalytic properties of two-component catalyst nickel oxide-cadmium oxide with the proportions of the components covering the whole composition region 0-100% were examined by studying the decomposition of hydrogen peroxide in aqueous solution on it. In the range 0-25 mol.% CdO, cadmium oxide is found to affect infavourably the ability of nickel oxide to chemisorb oxygen. The amount of the chemisorbed oxygen increases several times on gamma irradiation of the samples. The effect of cadmium oxide on the catalytic activity of the system shows up in fresh samples only indirectly via the changed amount of the oxygen chemisorbed. In older samples the initial catalytic activity of the system is changed, which can be explained based on the concept of bivalent catalytic centres in terms of the co-action of the catalytic centres of the two oxides, which are in equilibrium. The irradiation of the system under study speeds up the processes leading to the establishing of this equilibrium which is thermally very stable, and results in a substantial increase of the catalytic activity of the samples investigated.

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