Synthesis of LaMnO{sub 3+{delta}} by firing gels using citric acid

Journal Article · Sat Feb 15 04:00:00 EST 1997 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1996.7229· OSTI ID:518424

Taguchi, Hideki; Matsu-ura, Shin-ichiro; Nagao, Mahiko ^[1]

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1. Okayama Univ. (Japan); and others

A gel was prepared by adding citric acid to an aqueous solution of lanthanum nitrate and manganese nitrate. From thermal analysis and IR measurement, the gel prepared with 0.0023 mol of citric acid is a mixture of LaMn(C{sub 6}H{sub 5}O{sub 7})(NO{sub 3}){sub 3}, La(NO{sub 3}){sub 3} {circ} xH{sub 2}O, and Mn(NO{sub 3}){sub 2} {circ} xH{sub 2}O; the gel with 0.007 mol of citric acid LaMn(C{sub 6}H{sub 5}O{sub 7})(NO{sub 3}){sub 3}; and the gel with 0.015 mol of citric acid is LaMn(C{sub 6}H{sub 5}O{sub 7}){sub 2}. Hexagonal perovskite-type LaMnO{sub 3+{delta}} was obtained by firing the gels. The specific surface area, the La/Mn ratio, and the catalytic activity for CO oxidation on LaMnO{sub 3+{delta}} were measured. The catalytic activity for CO oxidation on LaMnO{sub 3+{delta}} synthesized using citric acid is better than that on LaMnO{sub 3+{delta}} synthesized using poly (acrylic acid). For these results, citric acid is inferred to improve the crystallinity (regularity of the ions) of the LaMnO{sub 3+{delta}} surface.

• OSTI ID: 518424
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 129; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
20 FOSSIL-FUELED POWER PLANTS
33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
CARBON MONOXIDE
CATALYTIC EFFECTS
CHEMICAL PREPARATION
LANTHANUM OXIDES
MANGANESE OXIDES
OXIDATION
SPECIFIC SURFACE AREA
STOICHIOMETRY
THERMAL ANALYSIS