The effect of substituting La and Co with Ca and Ti in LaCoO3/KIT-6 on its properties and possible catalytic application in syngas conversion

LaCo1−x−yCuxTiyO3/KIT-6 perovskites: synthesis and catalytic behavior in syngas conversion to higher alcohols

“…The third and fourth thermal reduction effects can probably be attributed to the first stage of cobalt reduction Co 3+ → Co 2+ regardless of the copper cations. In this case, as we showed earlier, 20 the presence of two thermal effects is due to the spin state of cobalt in the perovskite structure. The first effect should be attributed to the reduction of high-spin Co S =2 3+ cations to the Co 2+ cations, and the second effect to the reduction of the low-spin Co S =0 3+ cations to the Co 2+ cations.…”

“…aSee in the literature. 20 bCo 2+ cations in the structure of Co 2 SiO 4 , which are formed in the presence of KIT-6 in the course of cobalt reduction. 20 cCo 2+ cations in the structure of perovskite containing Ti 4+ cations.…”

“…bCo 2+ cations in the structure of Co 2 SiO 4 , which are formed in the presence of KIT-6 in the course of cobalt reduction. 20 …”

“…Thus, at ∼670 °C, the cobalt cations are reduced from the structure of finely dispersed Co 2 SiO 4 , which is formed at an earlier stage of reduction during the interaction of the Co 2+ cations with the KIT-6 matrix, and at 760–790 °C, the Co 2+ cations located in the volume of titanium-containing perovskite are reduced. 20…”

“…Partially, copper with cobalt at position B of the ABO 3 perovskite structure was replaced by titanium cations, the introduction of which, as shown in our previous work, has a positive effect on increasing the specific surface area of cobalt-containing perovskites and changing the composition of various cobalt cations in the structure, which can affect the final properties of the catalysts. 20…”