Showing papers on "Palladium published in 1972"
1,832 citations
459 citations
TL;DR: In this paper, it is emphasized that metal dissolution currents should not be ignored when examining electrochemical processes on noble metals at anodic potentials, and evidence in support of an anodic mechanism for noble metal corrosion has been obtained from studies of the variation of dissolution rate with both potential and temperature.
394 citations
237 citations
TL;DR: In this article, superconducting transitions have been observed in the Pd-H and D-D systems up to temperatures of 9 and 11 K. The high concentrations necessary for superconductivity have been obtained by implanting H- or D-ions into the pd at liquid helium-temperatures.
Abstract: Superconducting transitions have been observed in the Pd-H and Pd-D systems up to temperatures of 9 and 11 K, respectively. The high concentrations necessary for superconductivity have been obtained by implanting H- or D-ions into the Pd at liquid helium-temperatures.
230 citations
TL;DR: In this article, the structures of N-phenylbenzaldimine with palladium(II) acetate in boiling acetic acid have been confirmed by IR and proton NMR data, which are different from those reported by Molnar and Orchin.
220 citations
216 citations
206 citations
TL;DR: In this article, the chloro and bromo complexes of palladium(II) have been calculated using a least squares program from spectrophotometric measurements at 222, 234.5 and 279 nm (chloride) and at 247, 265, and 332 nm (bromide).
183 citations
TL;DR: In this article, the influence of the catalyst support on the oxidation of methane over palladium has been studied using a microcalorimetric bead reactor, and it has been shown that the reactivity of water towards the catalytic support is an important factor governing the deterioration of catalytic activity.
Abstract: The influence of the catalyst support on the oxidation of methane over palladium has been studied using a microcalorimetric bead reactor. The nature of the support had no detectable influence on the catalytic activity during a given experiment, but was found to affect the long-term stability of the catalyst.Investigations have been made of the kinetics of the oxidation of methane over a palladium/thoria catalyst both in the absence and in the presence of the reaction products. Oxidation was found to be strongly inhibited by the water formed, which tended to cause permanent deactivation of the catalyst; there was also very slight inhibition by carbon dioxide. Measurements of the rates of co-oxidation of methane with other compounds showed that methanol reacted independently, whereas formaldehyde and carbon monoxide were both oxidized competitively.It has been shown that the reactivity of water towards the catalyst support is an important factor governing the deterioration of catalytic activity. In accordance with this there was no evidence of catalyst deactivation when methane was co-oxidized with methanol, which would be expected to displace water.
116 citations
TL;DR: In the presence of active-hydrogen compounds such as phenols, alcohols, carboxylic acids, primary and secondary amines and active methylene compounds, it is necessary to add phenol to obtain the exchange products as discussed by the authors.
Abstract: The allylic compounds (I), R1–O–R (R=allylic groups, R1=Ph, Me, PhCH2, MeCO), react with active-hydrogen compounds such as phenols, alcohols, carboxylic acids, primary and secondary amines and active methylene compounds, to give allylic derivatives of the active-hydrogen compounds by an intermolecular exchange of the allylic groups of I with the atom to which the active hydrogens are bonded in the presence of palladium catalysts. Allyl and substituted-allyl ethers are more reactive than the corresponding carboxylates. In the reactions of methyl and benzyl ethers, it is necessary to add phenol to obtain the exchange products in fairly good yields. Bis(triphenylphosphine) palladium chloride plus sodium phenoxide, palladium acetate plus triphenylphosphine, and zerovalent palladium complexes such as tetrakis (triphenylphosphine) palladium and (maleic anhydride)bis(triphenylphosphine)palladium are effective catalysts.
TL;DR: In this paper, active methylene compounds, such as acetylacetone and ethyl acetoacetate, reacted with 1,3-butadiene in the presence of palladium-diphosphine complex catalysts to yield two 1 : 1 adducts, 1 and 2.
Abstract: Active methylene compounds, such as acetylacetone and ethyl acetoacetate, reacted with 1,3-butadiene in the presence of palladium-diphosphine complex catalysts to yield two 1 : 1 adducts, 1 and 2. Primary and secondary amines also afforded two 1 : 1 adducts, 10 and 11. Isoprene, 1,3-pentadiene, and 2,4-hexadiene also reacted with the active methylene compounds and the amines in a manner similar to that of 1,3-butadiene. The most effective and easily available catalyst is the combination of PdBr2(Ph2PCH2CH2PPh2)2 and sodium phenoxide.
TL;DR: In this paper, the rate constants for the chloride and bromide anations of Pd(H2O)42+, PdCl42−, and PdBr42− have been determined at 15, 25 and 35 °C using a stopped-flow technique.
TL;DR: Although the catalytic properties of gold are surpassed by those of the Group VIII metals, especially palladium and platinum, possible applications of gold in catalytic processes have been widely studied, more especially for oxidative dehydrogenation.
Abstract: Although the catalytic properties of gold are surpassed by those of the Group VIII metals, especially palladium and platinum, possible applications of gold in catalytic processes have been widely studied, more especially for oxidative dehydrogenation. Alloys and mixtures of gold with the platinum group metals are also receiving increased attention, and the developments outlined here indicate a number of potential uses.
TL;DR: The preparation of organometallic compounds of nickel(II), palladium (II) and platinum(II) containing two chelate five-membered rings of type (A) as discussed by the authors is described.
TL;DR: In this paper, a method for the determination of palladium surface areas using hydrogen chemisorption is described, which is independent of the extent to which oxygen is preadsorbed on the metal surface.
TL;DR: In this article, the co-condensation reaction of atomic palladium with a dilute CO-argon mixture (1:1000) at 10°K yields intermediate carbonyls of palladium Pd(CO)n where n = 1−3 as well as very small amounts of PdCO)4.
Abstract: The co-condensation reaction of atomic palladium with a dilute CO–argon mixture (1:1000) at 10°K yields intermediate carbonyls of palladium Pd(CO)n where n = 1–3 as well as very small amounts of Pd(CO)4. Isotopic substitution experiments using 12C18O were used to aid the spectral assignments. The probabilities of forming the various Pd(CO)n carbonyl species as a function of the CO concentration in Ar are analyzed and compared with the experimental observations. An analysis of the diffusion kinetics demonstrates their usefulness in assigning bands to various species in a series of compounds such as Pd(CO)n. The data make possible the assignment of infrared absorptions at 2070, 2060, 2044, and 2050 cm-1 to tetrahedral (Td) Pd(CO)4, trigonal planar (D3h) Pd(CO)3, linear (D8h) Pd(CO)2 and linear (C8v) PdCO, respectively. Cotton–Kraihanzel force constants are calculated for Pd(CO)n and are compared with those for the analogous intermediate carbonyls of nickel, Ni(CO)n.
TL;DR: Copper wire exhibited a distinct inhibition of the motility and penetration of human spermatozoa in human cervical mucus, while palladium and stainless steel wires did not.
TL;DR: In the presence of halide, one mole of butadiene reacts with one moles of carbon monoxide to give the 3,8-nonadienoate as discussed by the authors.