NO reduction with NH3 under oxidizing atmosphere on copper loaded hydroxyapatite

Jemal, Jihène; Tounsi, Hassib; Chaari, Kamel; Petitto, Carolina; Delahay, Gérard; Djemel, Samir; Ghorbel, Abdelhamid

doi:10.1016/j.apcatb.2011.11.045

Cited by 18 publications

(5 citation statements)

References 22 publications

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“…The content of copper-doped Ca-HA could be also insufficient to be observed by XRD analysis. Similar results were observed by Jemal et al [24].…”

Section: Copper Depositionsupporting

confidence: 92%

“…These results suggested that the ionic exchange (IE) between copper(II) and Ca(II) might approach the equilibrium and this method did not allow the deposition of higher contents of copper on CaP-ini. Similar results were found by Jemal et al [24] for Ca-HA synthesized from soluble reactants ((NH 4 ) 2 HPO 4 and Ca(NO 3 ) 2 ), with copper dosages of 0-2.98 wt.%.…”

Section: Copper Depositionsupporting

confidence: 88%

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Synthesis, characterization, and thermo-mechanical properties of copper-loaded apatitic calcium phosphates

Martı́nez¹,

Minh²,

Weiss-Hortala³

et al. 2013

Composite Interfaces

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Copper is well known as a classical transition metal used in heterogeneous catalysis. In this study, copper-loaded apatitic calcium phosphates were prepared using incipient wetness impregnation (IWI) and ionic exchange (IE) methods. The interaction between copper precursor (copper nitrate trihydrate, Cu(NO 3) 2 •3H 2 O) and apatitic calcium phosphate (CaP) depended strongly on the preparation method and the content of copper-loaded. Using IE, copper(II) cations (Cu 2+) were incorporated in the apatitic structure of CaP. The content of copper(II) cations seemed to be limited at about 2.2 wt.%. Calcination at 400°C had no influence on the solids obtained by the IE method. Using IWI, the deposition of a theoretical copper content of 2 wt.% led to the incorporation of copper(II) cations in the apatitic structure of CaP by IE with Ca 2+ , despite the low quantity of aqueous solvent used. Therefore the resulting product was similar to that obtained by IE. When the theoretical copper content rose to 20 wt.%, the entire amount of copper precursor molecules were largely deposited, which resulted in the formation of copper oxide particles (CuO) after air calcination at 400°C. Thermo-mechanical analysis study showed that the presence of copper oxide did not modify the thermal shrinkage of the initial calcium phosphate. On the other hand, thermal shrinkage was much more important in the case of CaP substituted with copper(II) cations.

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“…The content of copper-doped Ca-HA could be also insufficient to be observed by XRD analysis. Similar results were observed by Jemal et al [24].…”

Section: Copper Depositionsupporting

confidence: 92%

Section: Copper Depositionsupporting

confidence: 88%

Synthesis, characterization, and thermo-mechanical properties of copper-loaded apatitic calcium phosphates

Martı́nez¹,

Minh²,

Weiss-Hortala³

et al. 2013

Composite Interfaces

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“…Calcium hydroxyapatite (Ca–HA, Ca 10 (PO 4 ) 6 (OH) 2 ) continues to attract much attention because of its numerous applications in the fields of biomaterial, − heterogeneous catalysis, − gas sensors, , and wastewater treatment, etc. , Thus, much work has been done on the synthesis of Ca–HA using different methods such as solid–solid reaction, , ultrasonic spray freeze–drying, or spray–drying techniques generating Ca–HA powder of controlled morphology, sol–gel technique, − precipitation in aqueous solution, − emulsion route, , microwave-assisted synthesis, synthesis under hydrothermal conditions, , or synthesis using templates, etc. , The precipitation of orthophosphate species by a calcium source in an aqueous solution seems to be the most general technique to prepare Ca–HA powder particles. By this route, water-soluble calcium sources such as calcium nitrate, calcium chloride, or calcium acetate are preferred because of the resulting homogeneity of the reaction medium.…”

Section: Introductionmentioning

confidence: 99%

One-Step Synthesis of Calcium Hydroxyapatite from Calcium Carbonate and Orthophosphoric Acid under Moderate Conditions

Minh

Trân

Nzihou

et al. 2013

Ind. Eng. Chem. Res.

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Calcium hydroxyapatite (Ca−HA) is a versatile material which can be used in several applications. This study aimed to investigate the one-step synthesis of Ca−HA using solely calcium carbonate as-is and orthophosphoric acid as widely available and low cost initial reactants. The stirring rate and quantity of water had only some slight effects on the reaction rate. On the other hand, the reaction temperature influenced strongly the decomposition of the initial calcium carbonate particles and therefore the composition of the solids obtained. At 25−60°C, high contents of calcium carbonate remained in the solid products even after a long reaction time of 168 h. At 80°C, the decomposition of calcium carbonate was nearly complete after 24 h of reaction. Brushite (CaHPO 4 •2H 2 O) and octacalcium phosphate (OCP, Ca 8 (HPO 4) 2 (PO 4) 4 •5H 2 O) were the main intermediates of the reaction. When the decomposition of calcium carbonate was complete (80°C, 24 h), stoichiometric Ca−HA was obtained, with some little amounts of carbonate-containing apatites of both A-type and B-type. Carbon dioxide was the only by-product of the reaction, and no water rinsing was required for the purification of products. metal nanoparticles is planned, as is the use of Ca−HA gel for water and gas purification processes.

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“…As the Cu content increased, it could have altered the active surface of Pd by the alloying effect to form several mixed oxides Pd x Cu y O during the calcination at 500 °C for 4 h in the preparation of catalysts. These mixed oxides suppressed the H 2 adsorption of Pd and led to the shifts in TPR profiles from a lower temperature of 120 °C to a higher temperature of 170 °C. − In the 10Cu/HAP, there are three reduction peaks at the lower temperature than 500 °C, which can be characterized as the reduction of copper species on the surface, , while the peak appears around 570 °C can be assigned to the reduction of copper species coordinated in the HAP framework or in solid phase-libethenite denoted as Cu 2 (OH)(PO 4 ). , Particularly, the peak at around 260 °C and its shoulder at about 360 °C can be ascribed to the reduction of highly dispersed Cu 2+ and bulk Cu 2+ with large particle size. − Therefore, in the 6Cu–4Pd/HAP and 8Cu–2Pd/HAP with high loading Cu content, the reduction peaks are broader than other bimetallic catalysts, contributing to the reduction of well-dispersed isolated CuO species in close vicinity with the mixed oxides. Based on the actual loading amount of metal determined by AAS, the extent of reduction was calculated (Table S9).…”

Section: Resultsmentioning

confidence: 99%

Highly Selective Synthesis of 1,4-Butanediol via Hydrogenation of Succinic Acid with Supported Cu–Pd Alloy Nanoparticles

Nishimura

2019

ACS Sustainable Chem. Eng.

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Hydroxyapatite (HAP)-supported Cu−Pd catalysts, denoted as Cu−Pd/HAP, have been discovered to be the efficient catalysts for hydrogenation of bioderived succinic acid in which the products are selectively tunable by adjusting the mixing ratio of Cu and Pd. Optimal performance toward 1,4-butanediol (BDO) is observed with Cu−Pd/HAP prepared with 8 wt %-Cu and 2 wt %-Pd, affording a selectivity of 82% at quantitative conversion. In contrast, the monometallic Cu and Pd catalysts are unable to produce BDO as the major product, but only γ-butyrolactone (GBL) with a low yield of 16% and butyric acid (BA) with a considerable yield of 78%, respectively, is formed. The formation of well-dispersed bimetallic alloy nanoparticles is revealed by transmission electron microscopy with energy-dispersive spectroscopy, H 2 -temperature programmed reduction, X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy studies. It is concluded that the fine alloying structure with high Cu contents is significant in favoring the formation of BDO via the ring-opening step of GBL rather than the hydrogenation of GBL to the nontarget product of BA. In addition, the CuPd alloy catalyst exhibits good recycling ability in four consecutive runs without significant loss in its activity.

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NO reduction with NH3 under oxidizing atmosphere on copper loaded hydroxyapatite

Cited by 18 publications

References 22 publications

Synthesis, characterization, and thermo-mechanical properties of copper-loaded apatitic calcium phosphates

Synthesis, characterization, and thermo-mechanical properties of copper-loaded apatitic calcium phosphates

One-Step Synthesis of Calcium Hydroxyapatite from Calcium Carbonate and Orthophosphoric Acid under Moderate Conditions

Highly Selective Synthesis of 1,4-Butanediol via Hydrogenation of Succinic Acid with Supported Cu–Pd Alloy Nanoparticles

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