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The adsorption of ammonia on boron phosphate has been studied by infrared spectroscopy. Dissociation of ammonia appears to occur and bands assignable to coordinately bonded ammonia and to NH 4 + were observed. Heating of the catalyst prior to adsorption decreases the amount of NH 4 + produced. Samples of boron phosphate with excess boron display coordinately bonded ammonia and the frequencies of these bands suggest a similarity to those found for ammonia adsorption on porous glass and silica impregnated with boron oxide. In contrast, the bands found with the samples of boron phosphate containing excess phosphorus are similar to those found for ammonia on alumina and silica-alumina.

A comparison between the activity and selectivities of dehydration of 2-butanol, 2-methyl-2-butanol, and 3-methyl-2-butanol has been made with the surface acidity of boron phosphate catalysts of compositions ranging from P B = 0.4 to 1.4 . The activity and the product distribution of the dehydration reactions of these alcohols were found to be sensitive to the change in the surface acid properties of the boron phosphate catalysts. The concentrations of trans-2-butene and 2-methyl-2-butene increase with increasing surface acidity, while those of the various remaining products show an inverse relationship to the acidity. The results are interpreted through a dominant carbonium ion mechanism with the possibility of an additional subsidiary process.

The oxidation of iodide by boron phosphate (BP) in nonaqueous solvent is shown to increase with phosphorus/boron (P/B) ratio for unpretreated BP, and for a tiven P/B ratio, to decrease with pretreatment temperature. Measurements of concentrations of acidic sites suggest that the weaker acidic sites would be more active in this process in BP.

The adsorption of pyridine, 2,6-dimethylpyridine (26DMPy), and 2,6-di-tert-butylpyridine (26DTBPy) has been studied on stoichiometric and nonstoichiometric boron phosphate by infrared spectroscopy. It has been shown that boron phosphate with P > B has a high percentage of Bronsted acid sites, while that with P < B contains predominately Lewis acid surface sites. Both 26DMPy and 26DTBPy interact with Bronsted and Lewis acid sites, and both can be displaced, the latter more easily, by pyridine.

The lithium borophosphate glasses were studied by 11 B and 31 P nuclear magnetic resonance spectroscopy. It was found that the fractions of BO 4 units present are greater than 0.5 and this result implies that there are boron phosphate units in the glasses. The boron phosphate unit, whose structure is different from that of BPO 4 , consists of one PO 4 unit, in which there is a P=O bond, and one BO 4 unit. The two tetrahedral units are linked by a shared oxygen atom. The excess of negative charge is distributed over the phosphate and borate units and is compensated by a cation. The majority of the glasses studied mainly consist of boron phosphate units. The fractions of BO 4 units vary with the different compositions of the glasses.

Temperature programmed desorption experiments have been performed on boron phosphate of eight different phosphorus/boron ( P B ) compositions from 0.89 to 1.40. Four consistently recurring peaks were found, each due to desorbed water, and the variations of the peak intensities and desorption activation energies with P B ratio were examined. This information, together with infrared spectroscopic data obtained earlier, was employed to provide tentative assignments of the surface species involved.

When gas phase deuterium is contacted with boron phosphate at elevated temperatures, HD and H2 are produced in the gas phase in proportions of approximately 2:1, respectively. The existence of exchangeable hydrogen atoms on the surface in quantities up to 1.3 × 10−5 mole/m2 is demonstrated, and empty sites, apparently not previously occupied by hydrogen atoms, can be shown to exist in concentrations as high as 1.5 × 10−5 mole/m2.

The gas-phase hydration of ethylene catalyzed by boron phosphate has been investigated at atmospheric pressure in the temperature range from 290 to 360 °C. A rate equation has been established from conversion data at four temperatures from 290 to 320 °C, which indicates that hydration proceeds by a surface reaction with preferential adsorption of water. The reaction rate and adsorption equilibrium constants have been calculated from the initial rate data by a nonlinear least-squares procedure.

The adsorption of krypton on two different samples of boron phosphate has been measured at 77, 80, 85, and 90°K over a pressure range from 10−4 Torr to the vapor pressure. Analysis of the data for the two samples demonstrates that the surface of boron phosphate is energetically heterogeneous but that differences between the surfaces of the two samples may not be as large as expected.

The preparation and some properties of high-surface-area boron phosphate have been studied. The effect of reaction parameters on the surface area of boron phosphate produced by the reaction of tri-n-propyl borate and orthophosphoric acid has been examined, and some surface and bulk properties of the solid have been studied. A one-to-one P 2 O 5 B 2 O 3 ratio produced a surface area of approximately 200 m2 g−1. Aging of the samples at room temperature for 500 days in screw cap vials and sealed glass tubes reduced the surface area by approximately 35 and 20%, respectively. Evacuation at temperatures up to 500 °C produced a weight loss of approximately 10%, while the surface area increased to 220 m2 g−1 at 300 °C.

Two kinds of boron phosphate manufacture, which give high acidity catalysts are described. One is based on an excess of H3PO4 in the starting mixture of H3BO3 and H3PO4, the other is based on reacting equimolar amounts of the acids in a boiling organic medium. The catalysts, so obtained, were tested in the gas-phase hydration of ethylene.

Boron phosphide has been synthesized from the elements at pressures and temperatures above 20 kbar and 1200 °C. The growth rate of crystals has been determined as a function of temperature and pressure. An activation energy of 49.27 kcal/mole has been obtained for the process. Crystals of boron phosphide have further been synthesized from the B-O-P system using mixtures of (1) boron, phosphorus and boron oxide; (2) boron and boron phosphate; and (3) boron and phosphorus pentoxide. Optical and scanning electron micrographs reveal details of the crystal morphology. Transmission measurements indicate the fundamental absorption edge of BP to lie at around 5 eV.

The adsorption of water on boron phosphate pretreated in vacuum at 100°C or 200°C has been measured at 15°C and at 25°C using a quartz spring system. This system is of interest because of the catalytic properties of boron phosphate in dehydration reactions (1–3).

Weight changes of boron phosphate (BPO 4 ) as a result of thermal treatment in vacuo at various temperatures have been measured and surface areas subsequent to such treatment and also following exposure to formic acid have been determined as part of a study of the decomposition of formic acid on boron phosphate. In general, the surface areas of BPO 4 increase with the increasing temperature of thermal treatment. However, following an exposure to decomposing formic acid, BPO 4 suffers a loss in surface area for all reaction temperatures. In general the results agree qualitatively for the two different samples of the catalyst used. Some definite trends do appear and it is suggested that the loss in surface area of BPO 4 during catalysis of the decomposition of formic acid is primarily due to the water, produced as a result of this decomposition, acting as a “sintering agent”.

Surface and bulk changes of solid boron phosphate on adsorption of water vapor have been examined with the scanning electron microscope. Amounts of water vapor up to 6% decreased the surface area up to 25% and appeared to be the result of changes in surface fine structure. More massive adsorption of water produced changes in both the surface and bulk structure of the particles of solid.

The decomposition of ethanol over boron phosphate has been studied from 255 to 370 °C. Ethylene and diethyl ether are the only significant products. The percent conversion to ethylene is a continuously increasing function of temperature while that to ether passes through a maximum at approximately 300 °C.

Surface properties of the dehydration catalyst, boron phosphate (BP), prepared by the reaction of triethyl borate and phosphoric acid, were investigated by the use of a microbalance system. During evacuation at elevated temperatures, weight changes of the BP were obtained. Nitrogen adsorption isotherms were measured after each treatment. Surface areas appear to increase, and reach a maximum in the range 200–300 °C. Weight changes are initially large but begin to level off as the temperature is increased. Ammonia isotherms were obtained at 25.00 °C on aliquots of the same BP sample after various pretreatments. Amounts of ammonia remaining adsorbed after evacuation overnight were taken as the quantity chemisorbed. An approximate value of 8.9 kcal/mole of ammonia was obtained for the heat of chemisorption of ammonia by measuring the pressure and weight change as the amount of chemisorbed ammonia is decreased on heating the BP to various temperatures in a closed system. Results are interpreted in terms of change of number of active sites with surface area and the deactivation of sites on loss of water.

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Attempts to substitute for silicon in the fluorphlogopite structure resulted in the synthesis of a fluorgermanium mica and a boron phosphate micalike orthorhombic crystal. The batch material contained Al2O3, MgO, MgF2, K2CO3, plus GeO2 for forming the fluorgermanium mica and BPO4 for forming the boron phosphate crystal. Optical analysis with a polarizing microscope and by X-ray diffraction verified the mica structure of the germanium crystal and disproved the mica structure of the boron phosphate crystal. The indices of refraction and unit-cell constants were determined for both crystals. A study of the electrical properties up to temperatures of 1000°F showed that the dielectric properties of the fluorgermanium mica were very similar to that of fluorphlogopite.

The reaction rate of adipic acid with ammonia over boron phosphate has been calculated by absolute reaction rate theory using a suggested mechanism and it is shown to be controlled by the adipic acid adsorption rate. A physisorption term is required in order that the calculated rate agrees with the experimental data at lower temperatures. In turn it is shown that the amount of physisorped material is related to the rate that catalyst activity is lost by assuming that the loss is caused by non-volatile species covering the lost sites.

The use of BPO4 in the synthesis of crystalline AlPO4 has been investigated. The best results are obtained if BPO4 and hydrated alumina are heated in molten KCl: at 1050°C the conversion degree of BPO4 into AlPO4 is >90% (in 4 h). The product consists of the tridymite AlPO4 form.

D2-Gas reagiert mit B-phosphat im Temperaturbereich von 623-741 K unter Freisetzung von HD und H2 im Verhaltnis 2:1.

The oligomerization of 1-decene was studied over six kinds of solid acid catalysts involving boron phosphate. Among them evacuated boron phosphate exhibited the highest oligomerization activity: superior to not only SiO2–Al2O3 but also a solid superacid, SO42−/ZrO2.

The skeletal isomerization of n-butene, catalyzed by boron phosphate, silicated boron phosphate, silicated alumina and boron phosphate supported on both alumina and silicated alumina was studied at 475°C. The silication of the boron phosphate seems to stabilize the surface area and substantially improves the catalytic abilities of the system. In the isomerization reaction, the silicated boron phosphate maintained high selectivity throughout the run, in opposition to the non-silicated catalyst. Furthermore, analysis of higher by products (C5+) is of great importance concerning the selectivity of the catalysts. Silicated boron phosphate produce mainly C8 as by products, while silicated alumina cracks the higher compounds to C5, C6, C7 etc.

Although boron phosphate calcined in air at 1173 K did not show any catalytic activity for the isomerization and oligomerization of cis-2-butene at 298 K, boron phosphate evacuated at 1173 K catalyzed the oligomerization without any detectable formation of 1-butene at 273 K.

The preparation and properties of gels of boron phosphate in concentrared sulphuric acid and oleum are described. Boron arscnate gels are also briefly discussed.

An account is given of the preparation and properties of some phosphors excited by ultra-violet radiation of short wavelength, namely boron phosphate activated by thallium, and some arsenate analogues of the halophosphates; also of "self-activated" vanadates excited by ultra-violet radiation of long wavelength.

The use of BPO4 in the synthesis of crystalline AlPO4 has been investigated. The best results are obtained if BPO4 and hydrated alumina are heated in molten KCl: at 1050°C the conversion degree of BPO4 into AlPO4 is >90% (in 4 h). The product consists of the tridymite AlPO4 form.

The infrared spectra of a number of alkenes chemisorbed on non-stoichiometric boron phosphate of P/B 1, where P/B is the molar ratio of phosphorus to boron, show similar absorption bands characteristic of saturated species. Spectra were obtained on adsorption of an alkene on a sample previously exposed to a poison, or vice versa. These spectra and results from measurements of the amount of alkene adsorbed on bare surfaces, and on those containing various amounts of preadsorbed pyridine, provide evidence that the adsorbed species is common to all the alkenes. These adsorbed species can be interpreted as carbonium ions of various kinds, which rapidly convert to tertiary carbonium ions, and subsequently to oligomeric forms of the hydrocarbons.

The reaction of HD on boron phosphate produces H2 and D2 in approximately 4/1 proportions. The concentrations of HD, H2 and D2 present in the gas phase at various times were employed to calculate rates of reaction and the loss of deuterium atoms from the gas phase as a function of time. This latter data, when combined with a suitable model for the rate of chemisorption, permitted activation energies for deuterium pickup by the surface as a function of surface coverage to be calculated. The two samples of boron phosphate employed yield data which suggest the existence of both empty and exchangeable sites for deuterium, and a distribution of exchange or hydrogen binding energies over the surface of each catalyst.

In the dehydration of 3,3-dimethyl- and 2,3-dimethyl-butan-2-ol, the formation of Hofmann alkanes (but-1-enes) is favoured by boron phosphate catalysts of relatively high surface acid concentrations, while those catalysts with lower acid concentrations promote the production of Saytzeff alkenes (but-2-enes); the activity and selectivity can be related to catalyst composition and surface acidity, and two simultaneously operative mechanisms, whose importance varies with catalyst composition, are tentatively proposed.

IN a recent communication in Nature, Rafter1 has directed attention to the presence of appreciable proportions of boron in samples of New Zealand coal ashes.

Trialkyl phosphates react with boron tribromide to yield alkyl bromides and a residue which affords tetragonal boron phosphate on ignition above 520°. Alkyl halide formation is more rapid than with boron trichloride. The isomeric purity of the bromides first formed is in accord with intermediate complex formation rather than bromine–alkoxyl exchange, at least for the n-alkyl esters and for tri-1-methylheptyl phosphate in petroleum solvent. In the absence of solvent, s-alkyl esters (1-methylbutyl, 1-ethylpropyl, and 1-methylheptyl) give bromides with much rearrangement.