TY - JOUR

T1 - 1 H and 93 Nb Solid-State NMR and IR Study of Acidity of Nanodisperse Nb 2 O 5 ·nH 2 O

AU - Yakovlev, I. V.

AU - Papulovskiy, E.

AU - Paukshtis, E. A.

AU - Bondareva, V. M.

AU - Toktarev, A. V.

AU - Zaikovskii, V. I.

AU - Lapina, O. B.

PY - 2019/4/1

Y1 - 2019/4/1

N2 - Niobium oxide hydrate is a promising material for various heterogeneous catalytic processes due to its strong acidity and stability in aqueous medium. While different synthesis conditions may lead to various particle morphologies, the effect of morphology of Nb 2 O 5 ·nH 2 O particles on their acidic properties is not fully understood yet. In this paper, we have successfully synthesized and characterized nanodisperse niobium oxide hydrate. Using infrared (IR) spectroscopy, we demonstrated that the sample exhibits strong Brønsted acidity close in strength to sulfuric acid. Furthermore, solid-state nuclear magnetic resonance (NMR) spectroscopy in combination with ab initio calculations gave additional insight into the nature of strong acidic sites and proved to be a useful tool for identification of acidic sites in Nb 2 O 5 ·nH 2 O systems. Thus, we have shown that it is not necessary to follow difficult high-temperature solid-state processes or processes with ammonia, which often contaminates the material, to synthesize highly acidic nanodisperse Nb 2 O 5 ·nH 2 O.

AB - Niobium oxide hydrate is a promising material for various heterogeneous catalytic processes due to its strong acidity and stability in aqueous medium. While different synthesis conditions may lead to various particle morphologies, the effect of morphology of Nb 2 O 5 ·nH 2 O particles on their acidic properties is not fully understood yet. In this paper, we have successfully synthesized and characterized nanodisperse niobium oxide hydrate. Using infrared (IR) spectroscopy, we demonstrated that the sample exhibits strong Brønsted acidity close in strength to sulfuric acid. Furthermore, solid-state nuclear magnetic resonance (NMR) spectroscopy in combination with ab initio calculations gave additional insight into the nature of strong acidic sites and proved to be a useful tool for identification of acidic sites in Nb 2 O 5 ·nH 2 O systems. Thus, we have shown that it is not necessary to follow difficult high-temperature solid-state processes or processes with ammonia, which often contaminates the material, to synthesize highly acidic nanodisperse Nb 2 O 5 ·nH 2 O.

KW - GENERALIZED GRADIENT APPROXIMATION

KW - NIOBIC ACID

KW - BRONSTED ACID

KW - NANOSHEETS

KW - CATALYSTS

KW - SURFACES

UR - http://www.scopus.com/inward/record.url?scp=85062569660&partnerID=8YFLogxK

U2 - 10.1007/s00723-019-01118-8

DO - 10.1007/s00723-019-01118-8

M3 - Article

AN - SCOPUS:85062569660

VL - 50

SP - 589

EP - 597

JO - Applied Magnetic Resonance

JF - Applied Magnetic Resonance

SN - 0937-9347

IS - 4

ER -