Carbon monoxide on palladium

CO Oxidation Catalyzed by Palladium. One of the best understood catalytic reactions occurring on a metal surface is the oxidation of carbon monoxide on palladium ... 

The oxidation of carbon monoxide on palladium single crystals at low pressures (between 10 and 10 torr) and temperatures ranging from about 450 to 550 K follows a rate law that is first order in O2 and inverse first order in CO. An appropriate sequence of elementary... 

Interestingly, the same catalyst is used for the conversion of furfiiral to furan, so that the question may be asked why THF is not made directly from furfural. The explanation lies in the fact that the conversion of furfural to furan liberates carbon monoxide which has such a high heat of adsorption on palladium that hydrogen cannot be adsorbed simultaneously. The heat of adsorption of carbon monoxide on palladium exceeds the heat of adsorption of hydrogen on palladium by 14 kcal/mole (58.576 kJ/mole). 

Y. Kikuzono, S. Kagami, S. Naito, T. Onish, and K. Tamaru, Selective Hydrogenation of Carbon Monoxide on Palladium Catalysts, Faraday Discuss. Chem. Soc. 72, 135 (1982). 

F. RUMPF, H. POPPA, M. BOUDART, Oxidation of carbon monoxide on palladium role of the alumina support , Langmuir, 4, p. 722-728,1988. 

It has been discovered that styrene forms a linear alternating copolymer with carbon monoxide using palladium II—phenanthroline complexes. The polymers are syndiotactic and have a crystalline melting point - 280° C (59). Shell Oil Company is commercializing carbon monoxide a-olefin plastics based on this technology (60). 

Leung L-WH, Weaver MJ. 1990. Influence of adsorbed carbon monoxide on the electrocatalytic oxidation of simple organic molecules at platinum and palladium electrodes in acidic solution A survey using real-time FITR spectroscopy. Langmuir 6 323-333. 

Electronic ligand effects are highly predictable in oxidative addition reactions a-donors strongly promote the formation of high-valence states and thus oxidative additions, e.g. alkylphosphines. Likewise, complexation of halides to palladium(O) increases the electron density and facilitates oxidative addition [11], Phosphites and carbon monoxide, on the other hand, reduce the electron density on the metal and thus the oxidative addition is slower or may not occur at all, because the equilibrium shifts from the high to the low oxidation state. In section 2.5 more details will be disclosed. 

In this chapter we will discuss some aspects of the carbonylation catalysis with the use of palladium catalysts. We will focus on the formation of polyketones consisting of alternating molecules of alkenes and carbon monoxide on the one hand, and esters that may form under the same conditions with the use of similar catalysts from alkenes, CO, and alcohols, on the other hand. As the potential production of polyketone and methyl propanoate obtained from ethene/CO have received a lot of industrial attention we will concentrate on these two products (for a recent monograph on this chemistry see reference [1]). The elementary reactions involved are the same formation of an initiating species, insertion reactions of CO and ethene, and a termination reaction. Multiple alternating (1 1) insertions will lead to polymers or oligomers whereas a stoichiometry of 1 1 1 for CO, ethene, and alcohol leads to an ester. 

Guryanova, O. S., Y. M. Serov, S. G. Gul yanova and V. M. Gryaznov. 1988. Conversion of carbon monoxide on membrane catalysts of palladium alloys Reaction between CO and H2 on binary palladium alloys with ruthenium and nickel. Kinet. and Catal. 29(4) 728-731. 

Measurements of the infrared spectra of carbon monoxide on supported palladium and Pd-Ag atoms (75a) shed light on the relative importance of the ensemble and ligand effects. Three CO absorption bands were observed on palladium and its alloys at 2060,1960, and 1920 cm-1. 

Compensation effects have been reported for the oxidation of ethylene on Pd-Ru and on Pd-Ag alloys (207, 254, 255) discussion of the activity patterns for these catalysts includes consideration of the influence of hydrogen dissolved in the metal on the occupancy of energy bands. Arrhenius parameters reported (208) for ethylene oxidation on Pd-Au alloys were an appreciable distance from the line calculated for oxidation reactions on palladium and platinum metals (Table III, H). Oxidation of carbon monoxide on Pd-Au alloys also exhibits a compensation effect (256). 

To demonstrate the potential available, simulations were carried out for the oxidation of carbon monoxide on a palladium shell catalyst with water desorption from 3A zeolite as a heat sink, based on experimentally validated model parameters for the individual steps (Figure 16). The calculations indicated that the reaction cycle time could be lengthened by a factor of 10, to a total 20 minutes, in comparison to a simple regenerative process with a similar amount of inert material instead of adsorbent in the fixed bed and for the same threshold for temperature deviation from the initial value. 

Acetylene hydrogenation. Selective hydrogenation of acetylene to ethylene is performed at 200°C over sulfided nickel catalysts or carbon-monoxide-poisoned palladium on alumina catalyst. Without the correct amount of poisoning, ethane would be the product. Continuous feed of sulfur or carbon monoxide must occur or too much hydrogen is chemisorbed on the catalyst surface. Complex control systems analyze the amount of acetylene in an ethylene cracker effluent and automatically adjust the poisoning level to prepare the catalyst surface for removing various quantities of acetylene with maximum selectivity. 

Nickel yields a tetracarbonyl when, in a finely divided condition, it is warmed in a current of carbon monoxide. Both palladium black and platinum black absorb carbon monoxide, yielding what appears to be a compound, although attempts to isolate the substance have not as yet proved successful. On heating to 250° C. the substances decompose, evolving carbon monoxide. 

The interaction of carbon monoxide with palladium salts produces under rela tively mild (but rigorously anhydrous) conditions such species as [Pd(CO)Cl2 ] 2, [Pdj CU(CO)j and probably, under higlier carbon monoxide pressure, species such as Pd(CO)2 CI3. Only under severe conditions are reduced species such as [Pd(CO)Xlrt X = Br. Cl formed, but since the catalytic reaction is carried out under a relatively mild carbon monoxide pressure, it is rather improbable that such reduced species are present in considerable amounts. For a general discus sion of the mechanism, however, the characteri .ation of the exact nature of the palladium(Il) carbonyl complexes formed m sint is irrelevant, ( nerally speaking, carbon monoxide coordination to a Pd(U) ion will produce a facile nucleophilic attack on CO by the alcohol. The question of whether such an attack is produced by free alcohol or by a palladium bonded alkoxy group, is worth examination. 

Palladium nanoparticles (nm-Pd) were synthesized by ship-in-a-bottle technique in supercages of NaA zeolite. The behaviors of electrodes of thin film of nm-Pd accommodated in NaA zeolite were characterized by cyclic voltammetry. The results illustrated that the nm-Pd possess particular properties for hydrogen reaction, i.e. in contrast to hydrogen absorption on massive palladium electrode, the surface processes of hydrogen adsorption-desorption become the dominant reaction on electrodes of thin film of nm-Pd. The processes of adsorption and desorption of carbon monoxide on the electrodes were studied using in situ electrochemical FTIR reflection spectroscopy. It has been revealed that in comparison with CO adsorbed on a massive Pd electrode, the IR absorption of CO adsorbed on nm-Pd particles accommodated in NaA zeolite has been enhanced to about 36 times. 

Figure 1. Infrared absorptions of carbon monoxide on (a) colloidal palladium (18A) and (b)colloidal platinum (<10A). 1 wt solutions in methylcyclo-...

Al-Ammar AS, Webb G (1978) Hydrogenation of acetylene over supported metal catalysts Part 1 - Adsorption of [ C] Acetylene and [ C] ethylene on silica supported rhodium, iridium and palladium and alumina supported palladium. J Chem Soc Earaday Trans 74 195 Al-Ammar AS, Webb G (1979) Hydrogenation of acetylene over supported metal catalysts Part 3 - [ C] tracer studies of the effect of added ethylene and carbon monoxide on the reaction catalyzed by silica-supported palladium, rhodium and iridium. J Chem Soc Faraday Trans 75 1900... 

Galwey AK, Bettany DG, Mortimer M (2006) Kinetic compensation effects observed during oxidation of carbon monoxide on y-alumina supported palladium, platinum, and rhodium metal catalysts toward a mechanistic explanation. Int J Chem Kin 38 689... 

Preparation.1 This rr-allylic palladium chloride complex is formed in high yield by the action of carbon monoxide on a solution of allyl chloride in methanol containing sodium chloropallidate. 

This type of reactor has been used in the past to study solid-catalyzed gaseous reactions. Tajbl, Simons, and Carberry (3) used a CSTCR to study the highly exothermic oxidation of carbon monoxide on a commercial palladium catalyst. Ford and Perlmutter (2) used a CSTCR with a catalytic wall to study sec-butyl alcohol dehydrogenation. In both studies, the authors found that data were obtained more easily and accurately with a CSTCR. 

F. Sakamoto, Effect of carbon monoxide on hydrogen permeation in some palladium-based alloy membranes, Int. J. Hydrogen Energy 1996, 21(11/12), 1017-1024. 

The alkaloid sendaverine (6) has been prepared by reduction and debenzyl-ation of the amide (5) obtained by the action of carbon monoxide and palladium(ll) acetate on N-4-methoxybenzyl-j8-2-bromo-4-benzyloxy-5-methoxyphenyl-ethylamine." Sendaverine and its N-oxide have been isolated from Corydalis gortschakoviif ... 

Ladas, S., Poppa, H. Boudart, M. The adsorption and catalytic oxidation of carbon monoxide on evaporated palladium particles. Surface Science 102, 151-171 (1981). Kieken, L. Boudar, M. In New frontiers in catalysis Proceedings of the 10th international congress on catalysis, Budapest, July 19-24, 1992, Studies in surface science and catalysis, Guczi, L., Solymosi, F. Tetenyi, P. (Eds.), Elsevier, Amsterdam, (1993). 

Further reports by Dobos et al (33,34) confirmed the initial results, but also showed that the response of the device was variable, depending on its previous history. The authors predicted a response characteristics of the device based on a Langmuir type of adsorption of the carbon monoxide on to the palladium surface ... 

Wong YT, Hoffmann R (1991) Chemisorption of carbon monoxide on three metal surfaces nickel (111), palladium(l 11), and platinum(l 11) a comparative study. J Phys Chem 95 859-867... 

Patterson, M., Angove, D. and Cant, N. (2000). The effect of carbon monoxide on the oxidation of four Cg to Cg hydrocarbons over platinum, palladium and rhodium, Appl. Catal. B Environmental, 26, pp. 47-57. 

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