Cobalt-lanthanum catalyst precursors for ammonia synthesis: determination of calcination temperature and storage conditions

Abstract

A thermal decomposition of a cobalt-lanthanum catalyst precursor containing a mixture of cobalt and lanthanum compounds obtained by co-precipitation were studied using thermal analysis coupled with mass spectrometry (TG-MS). Studies revealed that the calcination in air at 500 o C is suffi cient to transform the obtained cobalt precipitate into Co 3 O 4 , but it leads to only partial decomposition of lanthanum precipitate. In order to obtain Co/La catalyst precursor containing La 2 O 3 the calcination in air at the temperature about 800 o C is required. However, it is unfavorable from the point of view of textural properties of the catalyst precursor. A strong effect of storage conditions on the phase composition of the studied cobalt-lanthanum catalyst precursor, caused by the formation of lanthanum hydroxide and lanthanum carbonates from La 2 O 3 when contacting with air, was observed.

On the Effect of Flash Calcination Method on the Characteristics of Cobalt Catalysts for Ammonia Synthesis Process

“…[26] Properly selected cobalt promoters are required to provide its activity in ammonia synthesis reaction. Rare earth oxides like ceria [27,28] or lanthana [29,30] were used as structural promoters able to stabilise cobalt in hcp form. [31,32] They provide low-energy nitrogen binding sites on the active phase crystals, [33] as well as mediate in electron transfer.…”

Synthesis, Spectroscopic, Thermal, and Catalytic Properties of Eight New Complexes of Metal(II) Formates or Propionates with Imidazole; Relationship between the Carbon Chain Length and Catalytic Activity

“…It is thus important to determine the relationship between structure and activity, which is currently one of the most promising strategies in new drugs and catalyst design. All four mentioned metals, cobalt [ 8 , 9 , 10 , 11 ], nickel [ 12 , 13 , 14 ], copper [ 15 , 16 , 17 ], and zinc [ 17 , 18 , 19 ] are crucial and widely used in catalysis. One of the important reactions, problematic from an industrial point of view, is the reaction of the oxidation of styrene.…”