Catalytic combustion of methane on BaZr(1−x)MexO3 perovskites synthesised by a modified citrate method

• Published in: Catalysis today Vol. 197; no. 1; pp. 236 - 242
• Main Authors: Gallucci, Katia, Villa, Pierluigi, Groppi, Gianpiero, Usberti, Nicola, Marra, Gianluigi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-12-2012; Elsevier
• Subjects: BaZrO3 based catalysts; Catalysis; Catalytic combustion; CH4 oxidation; Chemistry; Exact sciences and technology; General and physical chemistry; Modified citrate method; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Modified citrate method; Catalytic combustion; CH4 oxidation; BaZrO3 based catalysts; Methane; Perovskite type compound; Citrate; Oxides; High temperature; Solid solution; Powder; Synthesis; Technology; Oscillation; Oxidation; Chemical reactivity; Structure; Hysteresis; Catalytic reaction; CH; Crystals; based catalysts; Transition metal; X ray diffraction; Heterogeneous catalysis; Aluminates; BaZrO; Gas turbine; Catalyst
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2012.08.034

The adopted citrate method allows for the preparation of several Me-substituded (Me=Mn, Ni, Ru, Rh, Pd, Pt, Co) BaZr(1−x)MexO3 perovskites, with almost monophasic composition, good morphological properties and some activity in CH4 combustion after calcination. [Display omitted]
► BaZr(1−x)MexO3 systems prepared by a modified citrate method were fully characterised by XRD profile fitting, BET analysis and TPC of methane. ► The investigated systems showed almost monophasic composition, good morphological properties and significant activity in CH4 combustion ► Very limited activity hysteresis between the heating and cooling conversion curves was observed ► BaZr(1−x)MexO3 systems show good potential to be used as finishing catalysts in catalytic combustion technology for gas turbine applications.
The catalytic combustion technology still lacks of catalytic systems stable at high temperatures, such as those of the gas turbine inlet in the last turbine generation. In this paper we tried to solve this problem by fitting transition metals inside a crystal structure which is known to be very stable.
Several oxides have been synthesised by a modified citrate method and investigated in the catalytic combustion of methane. Synthesised catalysts consist of a solid solutions with a perovskite structure of formula BaZr(1−x)MexO3, where Me=Rh, Pd, Mn, Ni, Ru, Pt, Co.
The goal of the work has been to provide the physicochemical, structural and morphological characterisation and the activity of these catalysts containing different amounts of transition metals, by means of BET, XRD profile fitting and TPC reactivity tests, respectively.
The synthesised powders showed a very limited hysteresis between the increasing and decreasing temperature curves and therefore should display no oscillations in working conditions.
These systems could be a high temperature alternative to the hexa-aluminates and could avoid the homogeneous post combustion volumes typical of the hybrid and XONON combustors.