Role of Chromium Introduced Into 12-molybdophosphates as Catalysts for Oxidation of Hydrocarbons

K  BRUCKMAN; J  HABER; F  TRIFIRO; J C  VEDRINE; R K  GRASSELLI; Hicham Idriss; H  KUNG

doi:10.1016/S0167-2991(08)64053-7

Role of Chromium Introduced Into 12-molybdophosphates as Catalysts for Oxidation of Hydrocarbons

K BRUCKMAN, J HABER, F TRIFIRO, J C VEDRINE, R K GRASSELLI, Hicham Idriss, H KUNG

Chemistry

Research output: Contribution to journal › Article › peer-review

6 Citations (Scopus)

Abstract

Chromium 12-molybdophosphate Cr[PMo12O40] was obtained with Cr3+ in cationic positions. On heating it transforms reversibly around 650K with the destruction of Keggin anions into an amorphous phase which is stable to about 750K, above which crystalline MoO3 appears. When after cooling the amorphous phase is exposed to water vapour, reconstructure of the initial phase takes place. XPS shows highly ionic bonding which results in hydroxylation of the surface and generation of strong acidic sites. Presence of chromium in cationic positions increases redox properties of Keggin anions rendering Cr[PMo] a highly active and selective catalyst for oxidation of methanol to formaldehyde, propane to propene and pentane to maleic anhydride. It is suggested that high activity in oxidative dehydrogenation of propane as opposed to high activity in insertion of oxygen in case of pentane may be due to the presence of amorphous phase.

Original language	English
Pages (from-to)	741-752
Number of pages	12
Journal	Studies in Surface Science and Catalysis
Volume	75
DOIs	https://doi.org/10.1016/S0167-2991(08)64053-7
Publication status	Published - 1993

Keywords

selective oxidation
acid

Access to Document

10.1016/S0167-2991(08)64053-7

Cite this

@article{957d172b2e9b490b91da51dda412448b,

title = "Role of Chromium Introduced Into 12-molybdophosphates as Catalysts for Oxidation of Hydrocarbons",

abstract = "Chromium 12-molybdophosphate Cr[PMo12O40] was obtained with Cr3+ in cationic positions. On heating it transforms reversibly around 650K with the destruction of Keggin anions into an amorphous phase which is stable to about 750K, above which crystalline MoO3 appears. When after cooling the amorphous phase is exposed to water vapour, reconstructure of the initial phase takes place. XPS shows highly ionic bonding which results in hydroxylation of the surface and generation of strong acidic sites. Presence of chromium in cationic positions increases redox properties of Keggin anions rendering Cr[PMo] a highly active and selective catalyst for oxidation of methanol to formaldehyde, propane to propene and pentane to maleic anhydride. It is suggested that high activity in oxidative dehydrogenation of propane as opposed to high activity in insertion of oxygen in case of pentane may be due to the presence of amorphous phase.",

keywords = "selective oxidation, acid",

author = "K BRUCKMAN and J HABER and F TRIFIRO and VEDRINE, {J C} and GRASSELLI, {R K} and Hicham Idriss and H KUNG",

year = "1993",

doi = "10.1016/S0167-2991(08)64053-7",

language = "English",

volume = "75",

pages = "741--752",

journal = "Studies in Surface Science and Catalysis",

issn = "0167-2991",

publisher = "Elsevier BV",

}

TY - JOUR

T1 - Role of Chromium Introduced Into 12-molybdophosphates as Catalysts for Oxidation of Hydrocarbons

AU - BRUCKMAN, K

AU - HABER, J

AU - TRIFIRO, F

AU - VEDRINE, J C

AU - GRASSELLI, R K

AU - Idriss, Hicham

AU - KUNG, H

PY - 1993

Y1 - 1993

N2 - Chromium 12-molybdophosphate Cr[PMo12O40] was obtained with Cr3+ in cationic positions. On heating it transforms reversibly around 650K with the destruction of Keggin anions into an amorphous phase which is stable to about 750K, above which crystalline MoO3 appears. When after cooling the amorphous phase is exposed to water vapour, reconstructure of the initial phase takes place. XPS shows highly ionic bonding which results in hydroxylation of the surface and generation of strong acidic sites. Presence of chromium in cationic positions increases redox properties of Keggin anions rendering Cr[PMo] a highly active and selective catalyst for oxidation of methanol to formaldehyde, propane to propene and pentane to maleic anhydride. It is suggested that high activity in oxidative dehydrogenation of propane as opposed to high activity in insertion of oxygen in case of pentane may be due to the presence of amorphous phase.

AB - Chromium 12-molybdophosphate Cr[PMo12O40] was obtained with Cr3+ in cationic positions. On heating it transforms reversibly around 650K with the destruction of Keggin anions into an amorphous phase which is stable to about 750K, above which crystalline MoO3 appears. When after cooling the amorphous phase is exposed to water vapour, reconstructure of the initial phase takes place. XPS shows highly ionic bonding which results in hydroxylation of the surface and generation of strong acidic sites. Presence of chromium in cationic positions increases redox properties of Keggin anions rendering Cr[PMo] a highly active and selective catalyst for oxidation of methanol to formaldehyde, propane to propene and pentane to maleic anhydride. It is suggested that high activity in oxidative dehydrogenation of propane as opposed to high activity in insertion of oxygen in case of pentane may be due to the presence of amorphous phase.

KW - selective oxidation

KW - acid

U2 - 10.1016/S0167-2991(08)64053-7

DO - 10.1016/S0167-2991(08)64053-7

M3 - Article

SN - 0167-2991

VL - 75

SP - 741

EP - 752

JO - Studies in Surface Science and Catalysis

JF - Studies in Surface Science and Catalysis

ER -

Role of Chromium Introduced Into 12-molybdophosphates as Catalysts for Oxidation of Hydrocarbons

Abstract

Keywords

Access to Document

Fingerprint

Cite this