Study of Water–Gas-Shift Reaction over La(1−y)SryNixCo(1−x)O3 Perovskite as Precursors

The performance of La(1−y)SryNixCo(1−x)O3 perovskites for the water gas shift reaction (WGSR) was investigated. The samples were prepared by the co- precipitation method and were performed by the BET method, XRD, TPR, and XPS. The catalytic tests were performed at 300 and 400 °C and H2Ov/CO = 2.3/1 (molar ratio). The sample with the highest surface area is La0.70Sr0.30NiO3. The XRD results showed the formation of perovskite structure for all samples, and the La0.70Sr0.30NiO3 sample also presented peaks corresponding to La2NiO4 and NiO, indicating that the solubility limit of Sr in the perovskite lattice was surpassed. The replacement of Co by Ni favored the reduction of the species at lower temperatures, and the sample containing Sr presented the highest amount of reducible species, as identified by TPR results. All samples were active, the Sr containing perovskite appearing the most active due to the highest surface area, presence of the La2NiO4 phase, and higher content of Cu in the surface, as detected by XPS. Among the samples containing Co, the most active one was that with x = 0.70 (60% of CO conversion).