Effect of rare-earth element modification on the performance of Cu/ZnAl catalysts derived from hydrotalcite precursor in methanol steam reforming

doi:10.1016/S1872-5813(18)30010-0

Journal of Fuel Chemistry and Technology

Volume 46, Issue 2, February 2018, Pages 179-188

https://doi.org/10.1016/S1872-5813(18)30010-0 Get rights and content

Abstract

Zn-Al layered double hydroxides (ZnAl-LDHs) were prepared on γ-Al₂O₃ by an in-situ synthesis method; with ZnAl-LDHs as the supports, a series of rare-earth element M (M = Y, La, Ce, Sm and Gd) doped M/Cu/ZnAl catalysts were then obtained through sequential wet impregnation method and used in the methanol steam reforming to produce hydrogen. The M/Cu/ZnAl catalysts were characterized by XRD, SEM-EDS, N₂ sorption, H₂-TPR, XPS and N₂O titration and the effect of rare-earth metal doping on their catalytic performance in the methanol steam reforming was then investigated. The results showed that the activity of Cu/ZnAl catalyst is closely related to the copper surface area and the reducibility; larger copper surface area and lower reduction temperature lead to a higher catalytic activity in methanol steam reforming. The addition of rare-earth elements including Ce, Sm and Gd can improve the copper dispersion, surface copper area and the catalyst reducibility, which is helpful to enhance the activity of M/Cu/ZnAl catalysts. Especially, the Ce/Cu/ZnAl catalyst exhibits the highest activity; over it, the methanol conversion is 100% (about 40% higher than that over the Cu/ZnAl catalyst) and the CO concentration in the product is only 0.39%, for the methanol steam reforming at 250°C.

References (33)

Y Ma et al.
Steam reforming of methanol for hydrogen production over nanostructured wire-like molybdenum carbide catalyst
Int J Hydrogen Energy
(2014)
S Sa et al.
Catalysts for methanol steam reforming-A review
Appl Catal B: Environ
(2010)
L Zhang et al.
Optimization of methanol steam reforming for hydrogen
J Fuel Chem Technol
(2013)
W Kim et al.
Methanol-steam reforming reaction over Cu-Al-based catalysts derived from layered double hydroxides
Int J Hydrogen Energy
(2017)
D Das et al.
Methanol steam reforming behavior of copper impregnated over CeO₂-ZrO₂ derived from a surfactant assisted coprecipitation route
Int J Hydrogen Energy
(2015)
A A Lytkina et al.
Influence of the support structure and composition of Ni-Cu-based catalysts on hydrogen production by methanol steam reforming
Int J Hydrogen Energy
(2015)
Y H Huang et al.
Catalysts prepared from copper-nickel ferrites for the steam reforming of methanol
J Power Sources
(2015)
G Busca et al.
Methanol steam reforming over ex-hydrotalcite Cu-Zn-Al catalysts
Appl Catal A: Gen
(2006)
C Z Yao et al.
Effect of preparation method on the hydrogen production from methanol steam reforming over binary Cu/ZrO₂ catalysts
Appl Catal A: Gen
(2006)
J P Shen et al.
Influence of preparation method on performance of Cu/Zn-based catalysts for low-temperature steam reforming and oxidative steam reforming of methanol for H₂ production for fuel cells
Catal Today
(2002)

D Hammoud et al.

Steam reforming of methanol over x% Cu/Zn-Al 400 500 based catalysts for production of hydrogen: preparation by adopting memory effect of hydrotalcite and behavior evaluation

Int J Hydrogen Energy

(2015)

S Patel et al.

Activity and stability enhancement of copper-alumina catalysts using cerium and zinc promoters for the selective production of hydrogen via steam reforming of methanol

J Power Sources

(2006)

J P He et al.

Cu supported on ZnAl-LDHs precursor prepared by in-situ synthesis method on γ-Al₂O₃ as catalytic material with high catalytic activity for methanol steam reforming

Int J Hydrogen Energy

(2017)

V Agarwal et al.

H₂ production by steam reforming of methanol over Cu/ZnO/Al₂O₃ catalysts: Transient deactivation kinetics modeling

Appl Catal A: Gen

(2005)

L Zhang et al.

CeO₂-ZrO₂-promoted CuO/ZnO catalyst for methanol steam reforming

Int J Hydrogen Energy

(2013)

L Zhang et al.

Effect of precipitation aging time on the performance of CuO/ZnO/CeO₂-ZrO₂ for methanol steam reforming

J Fuel Chem Technol

(2013)

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Citation Excerpt :
Yang et al. [19] showed that LDHs are compatible with coal and can combine with coal to form a crystalline structure on the surface, thereby blocking oxygen diffusion during spontaneous combustion. However, as an inorganic additive inhibitor, LDHs have problems such as a large amount of addition, low inhibition efficiency, and inability to large-scale production [20]. Therefore, LDHs are usually modified to improve their inhibitory properties.
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Formic acid assisted synthesis of Cu-ZnO-Al<inf>2</inf>O<inf>3</inf> catalyst and its performance in CO<inf>2</inf> hydrogenation to methanol
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The Cu/Zn/Al precursor by coprecipitation was treated with formic acid and then calcined in N₂ to obtain Cu-ZnO-Al₂O₃ catalyst (CZA) for the CO₂ hydrogenation to methanol. XRD, BET, TG-DSC, SEM, H₂-TPR, N₂O titration, XPS-AES and CO₂-TPD characterization techniques were used to analyze the phase composition, structural properties of the catalyst, the Cu specific surface area, the dispersion and valence of the Cu species. The results showed that the formic acid treatment tuned the ratio of Cu⁺ and Cu⁰, increased the number of medium-strong base sites in the catalyst, and raised the selectivity of methanol. Under reaction conditions of W/F(H₂/CO₂=70/23)=10 g·h/mol, t=200 °C and p=3 MPa, using Cu-ZnO-Al₂O₃ treated under HCOOH/Cu/(molar ratio)=0.8, the CO₂ conversion and the methanol selectivity were 6.7% and 76.3%, respectively.

View all citing articles on Scopus

: Foundation items: Supported by the National Natural Science Foundation of China (21671092, 21376237) and the Doctoral Scientific Research Foundation of Liaoning Province (201601322).

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RESEARCH PAPEREffect of rare-earth element modification on the performance of Cu/ZnAl catalysts derived from hydrotalcite precursor in methanol steam reforming

Abstract

Int J Hydrogen Energy

Appl Catal B: Environ

J Fuel Chem Technol

Int J Hydrogen Energy

Int J Hydrogen Energy

Int J Hydrogen Energy

J Power Sources

Appl Catal A: Gen

Appl Catal A: Gen

Catal Today

Int J Hydrogen Energy

J Power Sources

Int J Hydrogen Energy

Appl Catal A: Gen

Int J Hydrogen Energy

J Fuel Chem Technol

RESEARCH PAPER
Effect of rare-earth element modification on the performance of Cu/ZnAl catalysts derived from hydrotalcite precursor in methanol steam reforming