Formic acid decomposition catalytic

An elegant example of the combination of infrared studies with kinetic and thermodynamic data to determine the overall mechanism of a catalytic reaction is the catalytic decomposition of formic acid. Its decomposition on silica-supported nickel has been investigated by several groups namely, Fahrenfort and co-workers (17, 69), Clarke and Pullin (70) and Hirota, Kuwata, and Nakai (71). Fahrenfort and Coworkers identified the prominent bands at 1575 and 1360 cm-1 as typical of carboxylate ions by comparison with the spectrum of nickel formate. These bands were assigned to the symmetrical and asymmetrical vibration of the O-C-O group, respectively. They showed that these bands were absent in the spectrum of formic acid adsorbed on the support. The formation of carboxylate ion (1575 cm-1 band) at room temperature was faster than the response time of the instrument, which was about 10 sec. The proposed mechanism is ... 

PCSs obtained by dehydrochlorination of poly(2-dilorovinyl methyl ketones) catalyze the processes of oxidation and dehydrogenation of alcohols, and the toluene oxidation207. The products of the thermal transformation of PAN are also catalysts for the decomposition of nitrous oxide, for the dehydrogenation of alcohols and cyclohexene274, and for the cis-tnms isomerization of olefins275. Catalytic activity in the decomposition reactions of hydrazine, formic acid, and hydrogen peroxide is also manifested by the products of FVC dehydrochlorination... 

As early as 1923 Hinshelwood and Topley (27) noted the exceptionally erratic behavior of palladium foil catalyst in the formic acid decomposition reaction within 140-200°C. The initially very high catalytic activity decreased 102 times during the exposure of palladium to hydrogen, which is a product of the reaction. Though the interpretation does not concern the /3-hydride formation, the authors observation deserves mentioning. 

Volter and Alsdorf (52) obtained a relation of a very similar character for the dependence of the catalytic activity in formic acid decomposition on the composition of the nickel-copper alloys. However, extending the times of the alloy annealing for their better homogenization caused the maxima on the catalytic activity curves to disappear. 

There is an extensive literature relating to the role of surface intermediates in the heterogeneous catalytic decomposition of formic acid on metals and oxides (see Refs. 36, 522,1030,1042—1045). 

Formic acid at 98% had to be used as a solvent during a catalytic hydrogenation by using the palladium/carbon system. When the solvent came into contact with the catalyst there was a release of hydrogen. Does this accident result from the acid decomposition catalysed by palladium In this case the decomposition... 

Gold forms a continuous series of solid solutions with palladium, and there is no evidence for the existence of a miscibility gap. Also, the catalytic properties of the component metals are very different, and for these reasons the Pd-Au alloys have been popular in studies of the electronic factor in catalysis. The well-known paper by Couper and Eley (127) remains the most clearly defined example of a correlation between catalytic activity and the filling of d-band vacancies. The apparent activation energy for the ortho-parahydrogen conversion over Pd-Au wires wras constant on Pd and the Pd-rich alloys, but increased abruptly at 60% Au, at which composition d-band vacancies were considered to be just filled. Subsequently, Eley, with various collaborators, has studied a number of other reactions over the same alloy wires, e.g., formic acid decomposition 128), CO oxidation 129), and N20 decomposition ISO). These results, and the extent to which they support the d-band theory, have been reviewed by Eley (1). We shall confine our attention here to the chemisorption of oxygen and the decomposition of formic acid, winch have been studied on Pd-Au alloy films. 

Jacobs, G., Patterson, P.M., Graham, U.M., Crawford, A.C., Dozier, A., and Davis, B.H. 2005. Catalytic links among the water-gas shift, water-assisted formic acid decomposition, and methanol steam reforming reactions over Pt-promoted thoria. J. Catal. 235 79. 

Catalytic decomposition, of formic acid, 14 35 Catalytic effects, in isocyanate reactions, 13 393... 

Sabatier and Balandin had predicted a relationship between catal)dic activity and heat of adsorption. If a solid adsorbs the reactants only weakly, it will be a poor catalyst, but if it holds reactants, intermediates or products too strongly, it wiU again perform poorly. The ideal catalyst for a given reaction was predicted to be a compromise between too weak and too strong chemisorption. Balandin transformed this concept to a semiquantitative theory by predicting that a plot of the reaction rate of a catal)Tic reaction as a function of the heat of adsorption of the reactant should have a sharp maximum. He called these plots volcano-shaped curvesl This prediction was confirmed by Fahrenfort et al." An example of their volcano-shaped curve is reproduced in Fig. 9.1. They chose the catalytic decomposition of formic acid... 

The decomposition of formic acid is one of the most extensively studied catalytic reactions. Several excellent review articles have been written on the subject (76- 78). From a large number of studies on supported metal catalysts the following, and sometimes contradictory, observations were made ... 

The Catalytic Decomposition of Formic Acid P. Mars, J. J. F. Schollen, and P. Zwietering... 

On the assumption that the catalytically active area covered by the reactant remains unchanged over the experimental temperature range Hinshelwood and Topley (J.G.S. cxxiil. 1014, 1923) have determined the following energies of activation from the temperature coefficient and the relative reaction velocities for the decomposition of formic acid according to the equation... 

Adkins and Nissen, ] for example, found that alumina prepared in different ways exhibited very varying catalytic activity towards the decomposition of formic acid. This could hardly be due simply to the different surface areas of the several preparations, since the variation was not confined to the total speed of reaction but affected also the relative speeds of the two alternative decompositions which formic acid undergoes. Moreover, the apparent heats of activation varied from one kind of alumina to another. J... 

The methods for making allyl alcohol are many. It may be prepared by (a) the action of metals upon dichlorohydrin 1 (b) the reduction of acrolein 2 (c) the action of potassium hydroxide on trimethylene bromide 3 (d) the catalytic decomposition of glycerol with aluminum oxide 4 (e) the hydrolysis of allyl iodide 5 (/) the decomposition of glycerol triformate 6 (g) the action of formic acid upon glycerin 7 and (h) the action of... 

Krupay and Ross (272b), in a study of the decomposition of formic acid on manganese (II) oxide, demonstrate that manganese (II) formate is produced during reaction and discuss the probable role of this participant in the catalytic process. The reported Arrhenius parameters (log A, E) for the dehydration and dehydrogenation reactions were (28.7, 132) and (24.9, 87), respectively both points were close to the compensation line (Table V, K) characteristic of the breakdown of formic acid on oxides. 

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