The infra-red spectra of inorganic phosphorus compounds. Part II. Some salts of phosphorus oxy-acids
About: This article is published in Journal of The Chemical Society (resumed).The article was published on 1954-01-01. It has received 122 citations till now. The article focuses on the topics: Phosphorus.
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TL;DR: In this article, the mixtures of ammonium dihydrogenphosphate, manganese carbonate, and neodymium oxide in the mole ratios of P/(2Mn+3Nd)=1/2 and Mn/Nd=10/0, 9/1 and 8/2 were milled with planetary mill and the thermal behavior of milled samples was investigated with differential thermal analyses, X-ray diffraction, and Fourier transform infrared spectroscopy.
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01 Jan 1976
21 citations
TL;DR: In this article, the Raman spectra were measured and analyzed for crystalline W 2 O 3 (PO 4 ) 2 and factor group analysis indicated that the observed vibrational spectra can be interpreted better with the earlier determined space group P2 1 m−C 2 2h than with the space group p 2 1 − C 2 2.
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TL;DR: In this article, the role of rare earth elements in the formation of cyclo-tetraphosphate was investigated and surface properties, specific surface area, acid strength and amount of acid sites, catalytic activity for dehydration of 2-propanol and cracking / dehydrogenation of cumene, were measured to clarify the role in rare earth element in magnesium cyclotetraphophosphate.
Abstract: Basic copper or magnesium carbonate was mixed with phosphoric acid in the mole ratio of P/M=2 (M; Cu or Mg). Each mixture was transformed to cyclo-tetraphosphate by heating. A part of the basic copper or magnesium carbonate was replaced with a rare earth oxide (La2O3, CeO2, Pr6O11, Nd2O3, Sm2O3, Yb2O3, and Y2O3) in this system. These mixtures containing one of the rare earth oxides were heated and then the products were analyzed by XRD, FT-IR, and TG-DTA. It was observed in copper system that the product changed from cyclo-tetraphosphate to pyrophosphate by the addition of rare earth oxide used in this study. In magnesium system, magnesium cyclotetraphosphate was formed in spite of the addition of rare earth oxide. Surface properties, specific surface area, acid strength and amount of acid sites, catalytic activity for dehydration of 2-propanol and cracking / dehydrogenation of cumene, were measured to clarify the role of rare earth element in magnesium cyclo-tetraphosphate. INTRODUCTION Phosphates are transformed to other phosphates in hydrolysis and dehydration Received May 15, 2001; Accepted July 31, 2001 -139reactions at elevated temperatures 1-3). There are polyphosphate, cyclo-phosphate, and ultraphosphate in a group of condensed phosphates. Polyphosphate has a chain structure in which PO4 unit shares two oxygen atoms, cyclo-phosphate has a cyclic structure, and ultraphosphate has a network structure 4). Orthophosphate, polyphosphate, and ultraphosphate of rare earth elements were formed by heating a mixture of a rare earth oxide and phosphoric acid in Pa ratio =1 ,3, and 10 (R: rare earth element), respectively 1). However a rare earth cyclophosphate wasn't formed by only heating. It was formed from a sodium cyclophosphate solution and a rare earth nitrate solution 5,6). This salt was decomposed to ortho-, pyro-, triphosphate, and so on above 100•Ž For this reason, there is few study about surface properties of rare earth cyclo-tetraphosphates. Previously, magnesium, manganese, cobalt, nickel, copper, and zinc cyclotetraphosphates were synthesized and investigated on their surface properties and catalytic activities for the dehydration of 2-propanol 7). The transformation of aliphatic primary and secondary alcohols to olefins and / or carbonyl compounds has been studied over various catalysts 8-12). The dehydration occurs over acidic site, whereas the dehydrogenation occurs over basic or reducing sites. It is known that both dehydration and dehydrogenation occur in a 2-propanol conversion reaction over metal oxides and so on. 2-propanol is transformed to propylene over acid sites of materials and to acetone over basic Sites 7,13-18). Therefore, these reactions of 2propanol are used as a probe to characterize both acidic and basic properties. On the other hand, cumene cracking / dehydrogenation reaction is used to estimate Lewis and Bronsted acid sites on metal oxides and so on 18-20). Benzene and propylene are the cracking products mainly on Bronsted acid sites, whereas ƒ¿-methylstyrene is a dehydrogenation product chiefly over Lewis acid sites. The addition of rare earth elements gives higher functional properties to the material 21). In this work, formation of binary cyclo-tetraphosphate was studied by replacing of copper or magnesium with rare earth elements in synthesis of cyclotetraphosphates. Furthermore, surface properties of the mixed phosphates were investigated to clarify the role of rare earth elements.
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TL;DR: The influence of powder condition on the sintering behavior of copper phosphates was studied in this article, where the un-milled and milled samples were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy.
Abstract: Copper orthophosphate, Cu3(PO4)2, and cyclo-tetraphosphates, Cu2P4O12, were synthesized using phosphoric acid and basic copper carbonate, and then treated with a planetary mill for up to 360 minutes. The un-milled and milled samples were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. SEM images, particle size distribution, specific surface area, UV-Vis reflectance spectra were also used to evaluate the materials. The un-milled and milled materials were used to fabricate copper phosphate bulks by a hydrothermal hot pressing method. The influence of powder condition on the sintering behavior of the copper phosphates was studied.
20 citations