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Titolo:
Role of nitrogen on the acid-base properties of zirconophosphate (ZrPON) oxynitride catalysts
Autore:
Fripiat, N; Parvulescu, V; Parvulescu, VI; Grange, P;
Indirizzi:
Univain,holique Louvain, Lab Catalyse & Chim Materiaux Divises, B-1348 Louv Univ Catholique Louvain Louvain Belgium B-1348 iaux Divises, B-1348 Louv Univomaniarest, Fac Chem, Dept Chem Technol & Catalysis, Bucharest 70346, R Univ Bucharest Bucharest Romania 70346 l & Catalysis, Bucharest 70346, R
Titolo Testata:
APPLIED CATALYSIS A-GENERAL
fascicolo: 2, volume: 181, anno: 1999,
pagine: 331 - 346
SICI:
0926-860X(19990517)181:2<331:RONOTA>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
METAL-OXIDE SURFACES; X-RAY PHOTOELECTRON; ALUMINOPHOSPHATE OXYNITRIDES; KNOEVENAGEL CONDENSATION; MOLYBDENUM NITRIDE; DRIFTS; ALPON; PHASE; AREA; XPS;
Keywords:
ZrPON; acid-base properties; nitrogen species; basic oxygen;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Engineering, Computing & Technology
Citazioni:
61
Recensione:
Indirizzi per estratti:
Indirizzo: Grange, P UnivdCatholique Louvain, Lab Catalyse & Chim Materiaux Divises, Pl Croix Su Univ Catholique Louvain Pl Croix Sud 2-17 Louvain Belgium B-1348
Citazione:
N. Fripiat et al., "Role of nitrogen on the acid-base properties of zirconophosphate (ZrPON) oxynitride catalysts", APP CATAL A, 181(2), 1999, pp. 331-346

Abstract

Activation of amorphous zirconium phosphate powder by high temperature treatment under NH3 allows to prepare series of zirconium phosphate oxynitrides. The adjustment of the N/O ratio allows the tuning of the acid-base properties of these high surface area and amorphous catalysts. It is evidenced that the substitution of oxygen by nitrogen induces a decrease of the numberand strength of acid site while the basic character of the surface increases. By increasing the nitrogen content in the ZrPON powders, the strong acidic centres of ZrPO precursor are modified and a "soft" surface is obtainedwith good equilibrium between acid and basic sites of medium strength. In ZrPON with high N content, the basicity clearly dominates as numerous strong basic centres are identified. The basicity enhancement is directly connected to the presence of nitrogen atoms N3- anions and hydrogenated nitrogen species in the zirconophosphate structure. It is then proposed that in addition to nitride N present at the surface and in the bulk, some oxygen species may be also responsible of the most strongest basic sites. (C) 1999 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 11/07/20 alle ore 20:14:30