Propane anodic oxidation

The anodic oxidation of alkanes on a platinum anode in anhydrous hydrogen fluoride19 at low potentials is accompanied by exhaustive fluorination, with all of the hydrogen atoms being replaced by fluorine. Thus, the major fluorination products of methane and propane are carbon tetrafluoride and octafluoropropane, respectively. 

The anodic oxidation of 2,2-bis(ethylthio)propane producing acetone and an oxidation product of diethyl disulfide, claimed to be the corresponding disulfoxide, was reported many years ago [133]. A renewed interest in this reaction involving a C-S bond cleavage arose when bis(phenylthio)methane and some of its p-substituted ring derivatives were anodically oxidized in dry MeCN on Pt electrodes and afforded diaryl disulfides and formaldehyde, with the latter identified after aqueous workup [39, 134]. The same cleavage was observed when MeCN-H20 (9 1 v/v) was the solvent, but aryl benzenethiosulfonates were the main products [39] ... 

Fig. 1.5 The effect of electrocatalyst type upon the anodic oxidation of propane in 3 M sulfuric acid at 80 °C.

Fig. 1.7 Effect of electrode coatings (Pt+ Nafion , Pt+Cg-acid, and R+C 12-acid) upon the anodic oxidation of propane at 80 °C in 6.0 M CF3SO3H.

Variation in the rate of anodic oxidation of normal saturated hydrocarbons with the number of carbon atoms parallels the variation in the rate of diffusion of the hydrocarbon through the electrolyte. This holds for different electrolytes (CsF/HF, H3PO4, HF, H2SO4) and electrodes (Pt-black, Raney-Pt). The rates are low for methane, highest for ethane and propane and then gradually decrease . ... 

The use of low molecular weight Refs. 33-37 hydrocarbons such as methane, ethane, and propane was considered to be an economic alternative to the anodic oxidation of hydrogen in the fuel cell. Extensive research and development was undertaken in this area in the 1960s. 

Cyclopropanes appear to be slightly more susceptible to anodic oxidation than comparably substituted alkenes. The anodic oxidation of bicycles (256) provides an interesting method of obtaining the co-enoates (257), while the spirocyclo-propanes (258) only suffer cleavage of the three-membered ring. In all probability... 

Binder and others [230] found that Raney platinum was the best single catalyst for electrochemical oxidation of hydrocarbons. Data obtained by Bianchi [231], Grubb [232], and Cairns and Mclnemey [203], who compared the catalytic activities of various platinum blacks in the anodic oxidation of propane, are consistent with this conclusion. As found by Petrii and Marvet [100], the oxidation rate of methane decreases sharply on changing from platinum to other platinum catalysts. Bockris and Dahms [192] showed that the oxidation rate of ethylene decreases in the series Pt > Rh > Ir and Pd > Au, where platinum is considerably more active than palladium. It was found in [233] that the oxidation rate of propane in alkali decreases in the order Pd > Pt > Ag, and those of ethane ethylene, propylene, and n-butane decrease in the order Pt > Pd... 

Arakawa et al. [18] used GC-MS to investigate the products of anodic oxidation of PC containing various Li salts, and were able to identify COg, propanal, and both the cis- and tra 5 -2-ethyl-4-methyl-l, 3-dioxolane as decomposition products. They proposed the following reaction path ... 

The previous discussion has focused on the properties of perovskite materials rather than on their performance as anodes. The number of actual fuel-cell studies is more limited, but this literature has been reviewed recently by Irvine. Various perovskites have been investigated as potential SOFC anode materials however, these early efforts were hampered by low electrochemical activity toward methane oxidation,poor anode structure,or insufficient electrode conductivity. Most recently, Tao and Irvine demonstrated that an anode based on (Lao.75Sro.25)o.9Cro.5Mno.503 can provide reasonable power densities at 1173 K in 3% humidified CH4. Barnett and co-workers also reported stable power generation with methane and propane fuels on an anode based on LaCr03 however, they reported that the addition of Ni, in levels too small to affect the conductivity, was crucial in providing activity for the electrochemical oxidation reactions. 

We previously reported that there is no activity at an Au surface for the partial oxidation of propene to acrylaldehyde by surface oxygen supplied directly from the gas phase and, furthermore, that there is no substantial influence of applied potential on the acrylaldehyde-formation activity of the surface oxygen from the gas phase [6]. Acrylaldehyde formation from propane appears to be performed only by the active species generated electrochemically on the Au anode surface through the YSZ. It is likely that the Au surface catalyzed a thermal cracking of... 

Die anodische Oxidation sek. Amine an eincr Silber-Anode liefert neben Nitrilen und Al-koholen etwas Aldehyd141. Arbeitet man an einer Platin- und besonders an einer Gra-phit-Elektrode, sind die Ausbeuten hoher142 (z.B. 25% Propanal aus Dipropylamin). Fiir die Bildung eines Aldehyds ist die Anwesenheit von Wasser erforderlich. Bei Zusatz von Dideuterooxid entsteht aus Tripropylamin 2-Deutero-propanal (zum Mechanismus s.Lit.142, keine Ausbeuteangabe). 

An interesting observation of their studies on propane oxidation relates to the observed behavior at higher loads as the cell approaches a steady state. The group suggests that the formation of oxide films on the anode electrode structure affects the voltage response and steady state behavior of the cell above a critical current density, being similar to the type of oxide films observed as early as the 1920s with the electrolysis of formic acid, methanol, and formaldehyde. 

Biershcenk D, Pillai M, Lin Y, Barnett S (2010) Effect of ethane and propane in simulated natural Gas on the operation of Ni-YSZ anode supported solid oxide fuel cells. Fuel Cells 10 1129... 

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