TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preparation (claimed): Preparation of the perovskite (I) (preferably CeAlO3) involves low temperature citrate, co-precipitation and hydrothermal processes, where the temperature is less than 750 degrees C. The citrate process involves stirring an aqueous solution of cerium and aluminum nitrate in molar ratio Ce:Al 1:1 at 60 degrees C for 2 hours after the addition of citric acid in a little excess of the molar amount of Ce and Al; stirring and heating the resultant solution up to 80 degrees C to obtain a spongy material after evaporation of water; heating the obtained spongy material at 200 degrees C for 2 hours to decompose the organic matter; calcining the obtained material at 500 degrees C for 3 hours in air to form a precursor; and reducing the obtained precursor in a flow of H2 (4-30 ml/min) at temperature less than or equal to 750 degrees C for 5 hours to obtain CeAlO3 perovskite, where for noble/transition metal incorporation, the corresponding salt of the noble/transition metal in appropriate ratio is added to the initial metal solution mixture as described in the first stirring step to obtain CeAl1-y(B1)yO3-d. The co-precipitate process involves co-precipitating cerium and aluminum in 1:1 molar ratio in presence of KOH as precipitating agent by simultaneous addition and vigorous stirring at 80 degrees C forming a gel; adjusting the pH of the obtained gel to 9-10.5, aging the gel at 80 degrees C for 12 hours to obtain a precipitate; washing the obtained precipitate with water to obtain pH 7.5; drying the precipitate at 100 degrees C for 12 hours and calcining in air at 500 degrees C for 3 hours to form a precursor; and reducing the obtained precursor in a flow of H2 (4-30 ml/min) at temperature less than or equal to 750 degrees C for 5 hours to obtain CeAlO3 perovskite, where for noble/transition metal incorporation, the corresponding salt of the noble/transition metal in appropriate ratio is added to the initial metal solution mixture as described in the co-precipitating step to obtain CeAl1-y(B1)yO3-d. The hydrothermal process involves precipitating aqueous solutions of cerium and aluminum in the molar ratio 1:1 with ammonia solution to obtain a gel; transferring the obtained gel to teflon lined stainless steel autoclave and heating it at 200 degrees C in oven to obtain a precipitate; filtering and drying the precipitate at 100 degrees C followed by calcination in air at 500 degrees C to form a precursor; and reducing the obtained precursor in flow of H2 (4 ml/min) at temperature less than 750 degrees C at five hours to obtain CeAlO3 perovskite, where for noble/transition metal incorporation, the corresponding salt of the noble/transition metal in appropriate ratio is added to the initial metal solution mixture as described in the precipitating step to obtain CeAl1-y(B1)yO3-d. Preferred Definitions:    B1=at least one element selected from transition metals but not limited to Ni, Cu, Co, Fe, Mn, Ft, Pd, Rh, Ru, Ir, Ag or Au, where the noble metal is not sintered.    EXAMPLE - An aqueous solution of cerium nitrate (5.9 g), aluminum nitrate (5.1 g), and citric acid (7 g) were stirred at 60 degrees C for 2 hours. Then the solution was stirred and heated up to 80 degrees C to obtain a spongy material after evaporation of water. The obtained spongy material was heated at 200 degrees C for 2 hours to decompose the organic matter, and then calcined at 500 degrees C for 3 hours in air to form a precursor. The obtained precursor was reduced in a flow of H2 (30 ml/minute) at temperature less than 750 degrees C for 5 hours to obtain CeAlO3 perovskite.