Quantification of metallic area of high dispersed copper on ZSM-5 catalyst by TPD of H2

Carvalho, Marta Cristina Nunes Amorim de; Passos, Fábio B.; Schmal, Martín

doi:10.1016/s1566-7367(02)00195-4

Cited by 13 publications

(3 citation statements)

References 25 publications

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“…Moreover, the calculated Cu/Al ratio of the Cu-ZSM-5 and Cu-SSZ-13 sample is 0.38 and 0.14 respectively. At such ion-exchange levels, Cu dispersion is 100% in ZSM-5 [28] and the Cu species in SSZ-13 are dominantly monomers [29].…”

Section: Catalyst Characterisationmentioning

confidence: 99%

Copper-Modified Zeolites and Silica for Conversion of Methane to Methanol

et al. 2018

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Powder materials containing copper ions supported on ZSM-5 (Cu-Zeolite Socony Mobil-5) and SSZ-13 (Cu-Standard Oil synthesised zeolite-13), and predominantly CuO nanoparticles on amorphous SiO 2 were synthesised, characterised, wash-coated onto ceramic monoliths and, for the first time, compared as catalysts for direct conversion of methane to methanol (DCMM) at ambient pressure (1 atm) using O 2 , N 2 O and NO as oxidants. Methanol production was monitored and quantified using Fourier transform infrared spectroscopy. Methanol is formed over all monolith samples, though the formation is considerably higher for the copper-exchanged zeolites. Hence, copper ions are the main active sites for DCMM. The minor amount of methanol produced over the Cu/SiO 2 sample, however, suggests that zeolites are not the sole substrate that can host those active copper sites but also silica. Further, we present the first ambient pressure in situ infrared spectroscopic measurements revealing the formation and consumption of surface methoxy species, which are considered to be key intermediates in the DCMM reaction.

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Section: Catalyst Characterisationmentioning

confidence: 99%

Copper-Modified Zeolites and Silica for Conversion of Methane to Methanol

et al. 2018

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“…The surface area (SBET) was calculated using the Brunauer-Emmett-Teller (BET) equation. X-ray powder diffraction (XRD) analyses were carried using a Cu-Ka radiation ( [26]. Accordingly, the sample was reduced under a flow of 5% H2/Ar.…”

Section: Materials Characterizationsmentioning

confidence: 99%

“…The temperature programmed desorption with H2 was per formed to evaluate the surface copper area the dispersion of copper. This technique was used as an alternative to the N2O chemisorption since N2O multilayer adsorption on copper oxide and N2O dissociation by other catalyst components have been reported [26,28,29]. Additionally, the utilization of the H2 TPD procedure appears to be easier and precise when compared to other methods.…”

Section: Physicochemical Characterizationmentioning

confidence: 99%

CuO/ZnO catalysts for methanol steam reforming: The role of the support polarity ratio and surface area

Mateos-Pedrero

Silva

Tanaka

et al. 2015

Applied Catalysis B: Environmental

116

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The effect of surface area and polarity ratio of ZnO support on the catalytic properties of CuO/ZnO catalyst for methanol steam reforming (MSR) are studied. The surface area of ZnO was varied changing the calcination temperature, and its polarity ratio was modified using different Zn precursors, zinc acetate and zinc nitrate. It was found that the copper dispersion and copper surface area increase with the surface area of the ZnO support, and the polarity ratio of ZnO strongly influences the reducibility of copper species. A higher polarity ratio promotes the reducibility, which is attributed to a strong interaction between copper and the more polar ZnO support. Interestingly, it was observed that the selectivity of CuO/ZnO catalysts (lower CO yield) increases with the polarity ratio of ZnO carriers. As another key result, CuO/ZnOAc375 catalyst has proven to be more selective (up to 90%) than a reference CuO/ZnO/Al2O3 sample (G66-MR, Süd Chemie).The activity of the best performing catalyst, CuO/ZnOAc-375, was assessed in a Pd-composite membrane reactor and in a conventional packed-bed reactor. A hydrogen recovery of ca. 75% and a hydrogen permeate purity of more than 90% was obtained. The Pd-based membrane reactor allowed to improve the methanol conversion, by partially suppressing the methanol steam reforming backward reaction, besides upgrading the reformate hydrogen purity for use in HT-PEMFC.2

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Synthesis of 2-Methylpyrazine Over Highly Dispersed Copper Catalysts

Luo

Jing

et al. 2012

Catal Lett

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A series of CuCoAl catalysts were synthesized by co-precipitation and impregnation methods, tested in synthesis of 2-methylpyrazine (2-MP) and characterized by X-ray diffraction, N 2 adsorption, thermo-gravimetry analysis, H 2 -temperature-programmed reduction, dissociative N 2 O adsorption and temperature-programmed oxidation. The precursors prepared by co-precipitation method shows a well-crystallized hydrotalcite. The study proves that the calcination temperature of hydrotalcite has a significant effect on the catalyst surface area, crystallite size and copper dispersion. In comparison with catalyst prepared by impregnation, the catalyst prepared by co-precipitation method calcined at 500°C exhibits higher specific surface area, higher copper dispersion and the better reducibility. Consequently, CuCoAl catalyst derived from hydrotalcite is more active and selective for synthesis of 2-MP. Moreover, it shows the better stability due to the good resistance to coke formation.

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Quantification of metallic area of high dispersed copper on ZSM-5 catalyst by TPD of H2

Cited by 13 publications

References 25 publications

Copper-Modified Zeolites and Silica for Conversion of Methane to Methanol

Copper-Modified Zeolites and Silica for Conversion of Methane to Methanol

CuO/ZnO catalysts for methanol steam reforming: The role of the support polarity ratio and surface area

Synthesis of 2-Methylpyrazine Over Highly Dispersed Copper Catalysts

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