An XPS study of copper corrosion originated by formic acid vapour at 40% and 80% relative humidity

Cano, E.; Torres, C. L.; Bastidas, J. M.

doi:10.1002/1521-4176(200109)52:9<667::aid-maco667>3.0.co;2-h

Cited by 132 publications

(84 citation statements)

References 9 publications

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“…Agglomeration of bigger crystallites yield larger voids between interparticles which result in a decreased surface area for the copper-richer sample as indicated in N 2 physisorption experiments ( Fig. 4 and Table 1) [41,43,45,46].…”

Section: Microscopic Investigationsupporting

confidence: 84%

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Catalytic oxidation of styrene over Cu-doped hydrotalcites

Thảo

Huyen

2015

Chemical Engineering Journal

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Section: Microscopic Investigationsupporting

confidence: 84%

“…The Cu 2p 3/2 peak at 935.4 eV is much higher than the binding energy of Cu 2+ in CuO (932.5 eV) and very close to that in the lattice of copper containing-minerals [39,46,47]. For a higher copper content sample (TH04), XPS spectra appear more two shake-satellite signals at 944.8 and 963.8 eV as shown in Fig.…”

Section: Xps Analysismentioning

confidence: 99%

Catalytic oxidation of styrene over Cu-doped hydrotalcites

Thảo

Huyen

2015

Chemical Engineering Journal

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“…The Fe 2p spectra are composed of a narrow low-spin Fe(II) peak at about 707.0 eV, a band centered at 708.0 eV from surface Fe atoms bonded to sulphur, and three multiplets at about 708.8, 710.0, and 711.1 eV from Fe(III) oxyhydroxides (Nesbitt et al, 2000;Uhlig et al, 2001). Three components for oxygen and three for carbon that were related to oxidation and adventitious carbon contamination were detected (Cano et al, 2001). In total, three doublets were fitted for S 2p spectrum of polished pyrite in which a component at 161.5 eV and 162.7 eV is related to surface disulphide species.…”

Section: Surface Composition Of Collectors Treated Cu(ii) Activated Ssupporting

confidence: 89%

“…These two peaks are associated with C-O Chapter 3: Characterisation of Sphalerite and Pyrite Copper Activation 38 and C=O groups, respectively. The peaks of C1s spectra are assigned to three components that correspond to carbon atoms in different functional groups: the non-oxygenated ring C (C-C), the C in C-O bonds (C-OH), and the carbonyl C (C=O), which arise from hydrocarbon contamination (Cano et al, 2001). Charge corrections for all other components are made using the C-C binding energy position (284.8 eV) as an internal reference.…”

Section: Surface Composition Of Cu(ii)-activated Sphaleritementioning

confidence: 99%

Bubble attachment and Amyl Xanthate adsorption to copper-activated sphalerite

Ejtemaei¹

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Sphalerite (ZnS) is a primary source of zinc metal. It usually coexists with other sulphide minerals such as pyrite (FeS 2 ) and galena (PbS). Its concentration is accomplished by froth flotation using short-chain thiol collectors such as xanthate. Due to its unique chemical and structural characteristics, the concentration of sphalerite by flotation requires Cu-activation, which is a process of making the mineral susceptible to reactions with the thiol collectors. The high amount of copper sulphate consumption is a big challenge for zinc processing plants, and the parameters that lead to a significant amount of copper sulphate usage for sphalerite activation is not wellunderstood. Based on the literature review and zinc processing plants reports, process water quality and the presence of pyrite during sphalerite Cu-activation could be two main factors affecting the activation that are the main focus of this thesis.To develop insight into mechanisms of Cu-activation of sphalerite and pyrite, Cryogenic X-ray Photoelectron Spectroscopic (Cryo-XPS) and zeta potential measurements were applied. The Cryo-XPS results showed that Cu-activation of sphalerite was an ion exchange reaction with CuS-type layer formation, while pyrite Cu-activation was governed by redox reactions with CuFeS 2 -type layer development. Depth profiling after 10 min activation revealed Cu diffusion into the sphalerite lattice up to 10 nm, while the thickness of the activation product on pyrite surface was less than 3 nm. The zeta potential studies confirmed proposed surface products on the minerals by Cryo-XPS.Hydrophobicity and many other surface properties of Cu-activated sphalerite can be changed by dissolved ions available in the process water (e.g. calcium, magnesium and sulphate). The effect of Ca(NO 3 ) 2 , Mg(NO 3 ) 2 , MgSO 4 and CaSO 4 on the surface properties of Cu-activated sphalerite was studied using sessile drop Contact Angle (CA), Cryo-XPS and zeta potential measurements. The CA measurements showed that the hydrophobicity of sphalerite developed after Cu-activation, but the presence of 3×10 -2 M Ca(NO 3 ) 2 or Mg(NO 3 ) 2 or MgSO 4 decreased its hydrophobicity. The XPS data showed that the effect of these ions appeared to be the same, namely a decrease in Cu adsorption and polysulphide formation. Zeta potential measurements confirmed the presence of calcium and magnesium ions on the sphalerite surface.Sphalerite is not the only sulphide mineral whose flotation behaviour can be affected by the presence of Cu ions in solution. The possibility of inadvertent Cu-activation of pyrite and its undesirable flotation is one factor accounting for the effective separation of sphalerite from pyrite.The surface hydrophobicity and components of the Cu-activated sphalerite were measured to investigate Cu adsorption kinetics of sphalerite in the presence of pyrite using a novel experimental approach of High-Speed Video Microscopy (HSVM) and Cryo-XPS. HSVM method allowed for ii in-situ liquid film Drainage rate (DR) and bubble-mineral CA...

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“…3 and 4. In Cu 2p 3/2 spectrum, the two peaks at the binding energies of 531.2 and 533.4 eV correspond to Cu 1+ and Cu 2+ ions, respectively [33][34][35]. In Fe 2p 3/2 spectrum of the perovskite samples, the peaks at the binding energies of 710.1 and 712.1 eV correspond to Fe 3+ and Fe 4+ ions, respectively [36][37][38].…”

Section: Characterizationmentioning

confidence: 99%

An experimental and kinetic study of toluene oxidation over LaMn1−x B x O3 and La0.8A0.2Mn0.3B0.7O3 (A=Sr, Ce and B=Cu, Fe) nano-perovskite catalysts

Tarjomannejad

Farzi

Niaei

et al. 2016

Korean J. Chem. Eng.

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Catalytic oxidation of toluene over perovskite-type oxides of the general formula LaMn 1−x B x O 3 (B=Cu, Fe and x=0, 0.3, 0.7) and La 0.8 A 0.2 Mn 0.3 B 0.7 O 3 (A=Sr, Ce and B=Cu, Fe) was investigated, where the catalysts were synthesized by sol-gel auto combustion method. The catalysts were characterized by XRD, BET, H 2 -TPR, XPS, and SEM. Obtained XRD patterns confirmed the perovskites to be single-phase perovskite-type oxides. Specific surface areas of perovskites were obtained between 25-40 m 2 /g. The perovskite catalysts showed high activity for the toluene oxidation. Based on the results, Fe-containing perovskite catalysts exhibited higher activity than Cu-containing perovskite catalysts. The substitution of Sr and Ce in A-site of the perovskite catalysts enhanced their activity for toluene oxidation. Among different synthesized catalysts in this research, La 0.8 Ce 0.2 Mn 0.3 Fe 0.7 O 3 has the highest activity. Nearly complete elimination of toluene was achieved at 200 o C with this catalyst. Based on Langmuir-Hinshelwood mechanisms, kinetic studies were conducted on toluene oxidation, indicating LH-OS-ND (adsorption of reagents on same types of sites and non-dissociative adsorption of oxygen) as the most probable mechanism which could predict the experimental data with correlation coefficient of R 2 =0.9952.

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An XPS study of copper corrosion originated by formic acid vapour at 40% and 80% relative humidity

Cited by 132 publications

References 9 publications

Catalytic oxidation of styrene over Cu-doped hydrotalcites

Catalytic oxidation of styrene over Cu-doped hydrotalcites

Bubble attachment and Amyl Xanthate adsorption to copper-activated sphalerite

An experimental and kinetic study of toluene oxidation over LaMn1−x B x O3 and La0.8A0.2Mn0.3B0.7O3 (A=Sr, Ce and B=Cu, Fe) nano-perovskite catalysts

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