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Conversion of syngas to higher alcohols over nanosized LaCo0.7Cu0.3O3 perovskite precursors

Paper ID Volume ID Publish Year Pages File Format Full-Text
43524 45975 2007 12 PDF Available
Title
Conversion of syngas to higher alcohols over nanosized LaCo0.7Cu0.3O3 perovskite precursors
Abstract

Two LaCo0.7Cu0.3O3 perovskite catalysts synthesized by reactive grinding and by the citrate complex method have been characterized by X-ray diffraction (XRD), BET, SEM, H2-temperature-programmed reduction (TPR) and tested for the synthesis of higher alcohols and hydrocarbons from syngas. The ground sample shows a rather high surface area and nanometric particles. The coexistence of copper and cobalt in the perovskite lattice provides a highly dispersed bimetallic phase after pretreatment under hydrogen. Both samples were reduced in situ prior to being tested for the synthesis of alcohols and hydrocarbons. The catalytic activity and product distribution depend strongly on the process variables, alkali promoter, preparation method, and catalyst morphology. While the ground perovskite is rather selective for the synthesis of higher alcohols, the citrate-derived precursor produces mainly methane and light hydrocarbons in addition to 10–15 wt.% of alcohols. The optimum parameters for catalyst preparation and for alcohol synthesis were determined. Under the optimal reaction conditions, the alcohol productivity is in a broad range of 70–140 mg/gcat/h and the selectivity towards alcohols is about 40–45 wt.%. Both alcohols and hydrocarbons produced obey a classical Anderson–Schulz–Flory (ASF) plot carbon number distribution.The nanocrystalline perovskite precursor shows a better catalytic performance compared to the citrate-derived sample in terms of both alcohol selectivity and productivity. The catalytic stability of the ground perovskite is dependent not only on the crystal domain size (or the size of nanoparticles) and the amount of remnant sodium ions, but also strongly on the compactness of nanoparticles. The existence of slit-shaped spaces between primary nanoparticles and/or grain boundaries hinders the formation of long carbon chains, which are precursors for the formation of coke on the catalyst surface.

Graphical abstractThis article provides a systematic study of the synthesis of higher alcohols over nanocrystalline La(Co, Cu)O3 perovskite precursors. The optimum parameters for catalyst preparation and for alcohol synthesis were determined. Under the optimal reaction conditions, the alcohol productivity is in a broad range of 70–140 mg/gcat/h and the selectivity towards alcohols is about 40–45 wt.%. The catalyst morphology of the ground perovskite has strong effects on the catalyst stability as well as productivity.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
La-Co-Cu; Higher-alcohols; Co-Cu metal; Syngas; Stability; Perovskite
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Conversion of syngas to higher alcohols over nanosized LaCo0.7Cu0.3O3 perovskite precursors
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 326, Issue 2, 15 July 2007, Pages 152–163
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
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Any Questions? feel free to contact us