A spillover approach to oxidation catalysis over copper and manganese mixed oxides

Buciuman, Florina-Corina; Patcas, F.; Hahn, Thomas

doi:10.1016/s0255-2701(99)00053-7

Cited by 109 publications

(58 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2). A similar shape for this spectrum was observed for Mn 3+ oxides by Smith et al (1999), but according to Buciuman et al (1999), this band could also be due to the transformation of MnO 2 into Mn 3 O 4 under the laser during acquisition of the spectral data. Electron-microprobe results confirm that those Mn phases identified in our samples correspond to hydroxides or hydrated oxides.…”

Section: Morphological and Mineralogical Characteristics Of The Two Ssupporting

confidence: 74%

The Weathering of a Sulfide Orebody: Speciation and Fate of Some Potential Contaminants

Courtin-Nomade¹,

Grosbois²,

Marcus³

et al. 2009

The Canadian Mineralogist

View full text Add to dashboard Cite

Various potentially toxic trace elements such as As, Cu, Pb and Zn have been remobilized by the weathering of a sulfide orebody that was only partially mined at Leona Heights, California. As a result, this body has both natural and anthropogenically modified weathering profiles only 500 m apart. The orebody is located in a heavily urbanized area in suburban Oakland, and directly affects water quality in at least one stream by producing acidic conditions and relatively high concentrations of dissolved elements (e.g., ~500 mg/L Cu, ~3700 mg/L Zn). Micrometric-scale mineralogical investigations were performed on the authigenic metal-bearing phases (less than 10 mm in size) using electron-probe micro-analysis (EPMA), micro-Raman, micro X-ray absorption spectroscopy (mXAS), scanning X-ray diffraction (mSXRD) and scanning X-ray fluorescence (mSXRF) mapping techniques. Those measurements were coupled with classical mineralogical laboratory techniques, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Authigenic metal-bearing phases identified are mainly sulfates (jarosite, epsomite, schwertmannite), Fe (oxy-)hydroxides (goethite, hematite and poorly crystalline Fe products) and poorly crystalline Mn (hydr-)oxides. Sulfates and Fe (oxy-)hydroxides are the two main secondary products at both sites, whereas Mn (hydr-) oxides were only observed in the samples from the non-mining site. In these samples, the various trace elements show different affinities for Fe or Mn compounds. Lead is preferentially associated with Mn (hydr-)oxides and As with Fe (oxy-)hydroxides or sulfates. Copper association with Mn and Fe phases is questionable, and the results obtained rather indicate that Cu is present as individual Cu-rich grains (Cu hydroxides). Some ochreous precipitates were found at both sites and correspond to a mixture of schwertmannite, goethite and jarosite containing some potentially toxic trace elements such as Cu, Pb and Zn. According to the trace element distribution and relative abundance of the unweathered sulfides, this orebody still represents a significant reservoir of potential contaminants for the watershed, especially in the non-mining site, as a much greater proportion of sulfides is left to react and because of the lower porosity in this site.

show abstract

Section: Morphological and Mineralogical Characteristics Of The Two Ssupporting

confidence: 74%

The Weathering of a Sulfide Orebody: Speciation and Fate of Some Potential Contaminants

Courtin-Nomade¹,

Grosbois²,

Marcus³

et al. 2009

The Canadian Mineralogist

View full text Add to dashboard Cite

show abstract

“…Figure 4 comprises TPR profiles of Cu1Mn1-X samples. The Cu1Mn1-400 exhibited three peaks at 170, [30,31]. The XRD and FT-IR results showed above indicated that Cu1Mn1-400 did not form the Cu 1.5 Mn 1.5 O 4 phase; and the TPR profile also showed that both CuO and Mn 2 O 3 existed in the sample.…”

Section: Fourier Transform Infraredmentioning

confidence: 98%

Liquid-phase oxidation of toluene by molecular oxygen over copper manganese oxides

Zhou

et al. 2006

Catal Lett

View full text Add to dashboard Cite

Copper manganese oxides (Cu-Mn oxides) were prepared by coprecipitation method and characterized by several techniques, such as X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and Temperature-programmed reduction (TPR). Catalytic activities of the Cu-Mn oxides were tested by the oxidation of toluene with molecular oxygen in liquid phase and solvent-free conditions. The molar ratio of Cu:Mn in catalyst was optimized to be 1:1 and thus the corresponding crystalline material was designated as Cu 1.5 Mn 1.5 O 4 .

show abstract

“…Figure 4 comprises TPR profiles of Cu1Mn1-X samples. The Cu1Mn1-400 exhibited three peaks at 170C, 275 and 320°C, which can be ascribed to the reduction of CuO and the two reduction stages from Mn 2 O 3 to MnO via Mn 3 O 4 [30,31]. The XRD and FT-IR results showed above indicated that Cu1Mn1-400 did not form the Cu 1.5 Mn 1.4 O 4 phase; and the TPR profile also showed that both CuO and Mn 2 O 3 existed in the sample.…”

Section: Fourier Transform Infrared (Ft-ir)mentioning

confidence: 99%

Liquid-phase oxidation of toluene by molecular oxygen over copper manganese oxides

Zhou

et al. 2006

Catal Lett

View full text Add to dashboard Cite

Copper manganese oxides (Cu-Mn oxides) were prepared by coprecipitation method and characterized by several techniques, such as X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Temperature-programmed reduction (TPR). Catalytic activities of the Cu-Mn oxides were tested by the oxidation of toluene with molecular oxygen in liquid phase and solvent-free conditions. The molar ratio of Cu:Mn in catalyst was optimized to be 1:1 and thus the corresponding crystalline material was designated as Cu 1.5 Mn 1.5 O 4 .

show abstract

A spillover approach to oxidation catalysis over copper and manganese mixed oxides

Cited by 109 publications

References 13 publications

The Weathering of a Sulfide Orebody: Speciation and Fate of Some Potential Contaminants

The Weathering of a Sulfide Orebody: Speciation and Fate of Some Potential Contaminants

Liquid-phase oxidation of toluene by molecular oxygen over copper manganese oxides

Liquid-phase oxidation of toluene by molecular oxygen over copper manganese oxides

Contact Info

Product

Resources

About