Lamellar zirconium phosphates to host metals for catalytic purposes

2018 ◽  
Vol 47 (9) ◽  
pp. 3047-3058 ◽  
Author(s):  
Daniel Ballesteros-Plata ◽  
Antonia Infantes-Molina ◽  
Elena Rodríguez-Aguado ◽  
Pilar Braos-García ◽  
Enrique Rodríguez-Castellón
Keyword(s):  
Zirconium Phosphate ◽  
Noble Metals ◽  
Molar Ratio ◽  
Zirconium Phosphates

In the present study a porous lamellar zirconium phosphate heterostructure (PPH) formed from zirconium(iv) phosphate expanded with silica galleries (P/Zr molar ratio equal to 2 and (Si + Zr)/P equal to 3) was prepared to host noble metals.

scholarly journals Use of Zirconium Phosphate-Sulphate as Acid Catalyst for Synthesis of Glycerol-Based Fuel Additives

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 148 ◽  
Author(s):  
Maria Testa ◽  
Valeria La Parola ◽  
Farah Mesrar ◽  
Fatiha Ouanji ◽  
Mohamed Kacimi ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Zirconium Phosphate ◽  
Acid Catalyst ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Fuel Additives ◽  
Spent Catalyst ◽  
Glycerol Conversion ◽  
Zirconium Phosphates ◽  
Ft Ir

In the present work, zirconium phosphates and mixed zirconium phosphate–sulphate acid catalysts have been investigated in the acetylation of glycerol in order to obtain acetins as fuel additives. The following catalysts with chemical composition, Zr3(PO4)4, Zr(SO4)2, Zr2(PO4)2SO4, Zr3(PO4)2(SO4)3 and Zr4(PO4)2(SO4)5 have been prepared and characterized by acid capacity measurements, BET, XRD, FT-IR, XPS. The surface chemical composition in terms of P/Zr and S/Zr atomic ratios was monitored in the fresh and used catalysts. Zr3(PO4)2(SO4)3 and Zr4(PO4)2(SO4)5 showed the highest acidity associated with the synergic effect of two main crystalline phases, Zr2(PO4)2SO4 and Zr(SO4)2·4H2O. The reactions of glycerol acetylation were carried out by using a mass ratio of catalyst/glycerol equal to 5 wt% and molar ratio acetic acid/glycerol equal to 3:1. The glycerol conversion versus time was investigated over all the prepared samples in order to identify the best performing catalysts. Over Zr3(PO4)2(SO4)3 and Zr4(PO4)2(SO4)5 full glycerol conversion was achieved in 1 h only. Slightly lower conversion values were registered for Zr3(PO4)4 and Zr2(PO4)2SO4, while Zr(SO4)2 was the worst catalyst. Zr4(PO4)2(SO4)5 was the most selective catalyst and was used for recycling experiments up to five cycles. Despite a modest loss of activity, a drastic decrease of selectivity to tri- and diacetin was observed already after the first cycle. This finding was attributed to the leaching of sulphate groups as detected by XPS analysis of the spent catalyst.

Ion Transport in Alumina-Pillared Zirconium Phosphate

1992 ◽  
Vol 286 ◽  
Author(s):  
C. Criado ◽  
J.R. Ramos-Barrado ◽  
P. Maireles-Torres ◽  
P. Oliverapastor ◽  
A. Jimenez-Lopez ◽  
...  
Keyword(s):  
Ion Transport ◽  
Equivalent Circuit ◽  
Temperature Interval ◽  
Zirconium Phosphate ◽  
Lithium Ion ◽  
Charge Carriers ◽  
Impedance Method ◽  
Electrical Behaviour ◽  
Lithium Ions ◽  
Zirconium Phosphates

ABSTRACTA.c. conductivity of a novel large-pore alumina-pillared zirconium phosphate and some lithium ion exchanged samples have been measured by an impedance method. These materials have a conductivity in the range 10-5 to 10-9 Ω-1cm-1 higher than those of alumina-pillared tin phosphate and its lithium derivatives. The electrical behaviour of the pillared zirconium phosphates fits to an equivalent circuit composed by two subcircuits in parallel with a condenser. In a temperature interval (200-500°C), lithium ions are charge carriers and the conductivity increases when heating with activation energies between 0.99 and 1.22 eV.

Formation and Reactivity of Cu Particles on the Surface of Mixed Copper-Zirconium Phosphate

2015 ◽  
Vol 670 ◽  
pp. 76-81
Author(s):  
Nataliya V. Dorofeeva ◽  
Olga V. Vodyankina ◽  
Grigory V. Mamontov ◽  
Vladimir I. Zaykovskii
Keyword(s):  
Temperature Increase ◽  
Zirconium Phosphate ◽  
Phase Evolution ◽  
Temperature Treatment ◽  
Treatment Temperature ◽  
Zirconium Phosphates

Phase evolution of copper-containing zirconium phosphates during the temperature treatment up to 900 °C and formation of active Cu0 particles on the surface of these materials in H2/Ar flow were studied. The materials were characterized by XRD, TEM, TPR-H2 at different steps of treatment. Temperature increase up to 900 °C led to removal of oxygen from the CuZr4P6O24 structure with formation of Cu+-containing compounds. Materials treated by H2-containing flow at 600 °C contained Cu0 particles with sizes from 2 nm to 1 μm. Mixed copper-zirconium phosphate was shown to adsorb CO above 80 °C, while pre-reduced materials adsorbed it starting from 30 °C with formation of CO2 above 100 °C.

Zirconium Phosphate and Modified Zirconium Phosphates as Supports of Lipase. Preparation of the Composites and Activity of the Supported Enzyme

Langmuir ◽  
2002 ◽  
Vol 18 (23) ◽  
pp. 8737-8742 ◽  
Author(s):  
Francesca Bellezza ◽  
Antonio Cipiciani ◽  
Umberto Costantino ◽  
M. Elena Negozio
Keyword(s):  
Zirconium Phosphate ◽  
Lipase Preparation ◽  
Zirconium Phosphates

Heats of immersion and heat of H+/Cu2+ exchange for amorphous zirconium phosphate

1984 ◽  
Vol 49 (8) ◽  
pp. 1749-1755 ◽  
Author(s):  
Petar V. Ilić ◽  
Alexander Tolić ◽  
Vladimír Pekárek ◽  
Alexander Ruvarac
Keyword(s):  
Zirconium Phosphate ◽  
Calorimetric Measurement ◽  
Zirconium Phosphates ◽  
Heats Of Immersion

Heats of Immersion of amorphous and crystalline zirconium phosphates in water were determined, and heat of H+/Cu2+ exchange on amorphous zirconium phosphate at 298.15 K was obtained by direct calorimetric measurement.

scholarly journals Column Separation of Am(III) and Eu(III) by α-Zirconium Phosphate Ion Exchanger in Nitric Acid

2020 ◽  
Vol 4 (1) ◽  
pp. 14
Author(s):  
Elmo W. Wiikinkoski ◽  
Iiro Rautsola ◽  
Junhua Xu ◽  
Risto Koivula
Keyword(s):  
Zirconium Phosphate ◽  
Distribution Coefficients ◽  
Ion Exchanger ◽  
Molar Ratio ◽  
Experimental Conditions ◽  
Column Separation ◽  
Phosphate Ion ◽  
Trivalent Lanthanide ◽  
Separation Factors ◽  
Equimolar Solution

The trivalent lanthanide-actinide separations are a major challenge in reprocessing of nuclear fuels. To achieve this, commonly organic extractants and solvents are utilized in elaborate processes. Here we report a simple new method that can perform a supportive or alternative role. A nanocrystalline α-zirconium phosphate ion exchanger was utilized for Eu(III)/Am(III) column separation. Comprehensive preliminary studies were done using batch experiments to optimize the final separation conditions. The distribution coefficients for Eu were determined as a function of pH (from 0 to 3) and salinity (Na, Sr). The distribution coefficients for Am were determined as a function of pH, and Eu concentration, from 1:40 to 10,000:1 Eu:Am molar ratio. The exchanger always preferred Eu over Am in our experimental conditions. Separation factors (Eu:Am) of up to 400 were achieved in binary Eu-Am solution in pH 1. The breakthrough capacity was determined in dynamic column conditions using Eu: 0.3 meq∙g−1, which is approximately 4% of the theoretical maximum capacity. Two types of hot column separation tests were conducted: (i) binary load (selective Am elution), and (ii) continuous equimolar binary feed. In both cases separation was achieved. In (i), the majority (82% of the recovered 93%) of Am could be purified from Eu with extremely high 99.999% molar purity, while alternatively even more (95% of the recovered 93%) at a lower purity of 99.7 mol %. In (ii), up to 330 L∙kg−1 of the equimolar solution per mass of the exchanger could be treated with Am purity above 99.5 mol % in the total eluate. Alternatively, up to 630 L∙kg−1 above 95 mol %, or up to 800 L∙kg−1 above 90 mol % purities.

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