LaNiO3 Perovskite Synthesis through the EDTA–Citrate Complexing Method and Its Application to CO Oxidation

Abstract

A series of LaNiO3 materials were synthesized by the EDTA–citrate complexing method, modifying different physicochemical conditions. The LaNiO3 samples were calcined between 600 and 800 °C and characterized by XRD, SEM, XPS, CO-TPD, TG, DT, and N2 adsorption. The results evidence that although all the samples presented the same crystal phase, LaNiO3 as expected, some microstructural and superficial features varied as a function of the calcination temperature. Then, LaNiO3 samples were tested as catalysts of the CO oxidation process, a reaction never thoroughly analyzed employing this material. The catalytic results showed that LaNiO3 samples calcined at temperatures of 600 and 700 °C reached complete CO conversions at ~240 °C, while the sample thermally treated at 800 °C only achieved a 100% of CO conversion at temperatures higher than 300 °C. DRIFTS and XRD were used for studying the reaction mechanism and the catalysts’ structural stability, respectively. Finally, the obtained results were compared with different Ni-containing materials used in the same catalytic process, establishing that LaNiO3 has adequate properties for the CO oxidation process.

Toward Environmentally Benign Catalyst Composition: Effect of Fe Substitution on Crystal Structure and Redox Behavior in Lanthanum Cobaltite Catalysts for CO Oxidation

“…Figure a–c shows the in situ DRIFTS spectra of LaCoO 3 , LaCo 0.75 Fe 0.25 O 3 , and LaCo 0.30 Fe 0.70 O 3 at different temperatures, respectively, while the catalysts were exposed to the reaction mixture of 0.5% CO and 10% O 2 balanced in N 2 gas flow. Two vibration bands at approximately 2116 and 2175 cm –1 were observed for all catalysts at the lowest temperatures, corresponding to the P and R branches of gaseous CO, respectively. , Simultaneously, the progressive formation of CO 2 as a function of temperature can be observed for all catalysts by the intensity of the gas-phase CO 2 bands at 2360 and 2330 cm –1 . Moreover, several bands of symmetric and asymmetric vibrations attributed to different carbonate species, including monodentate, bidentate, bridged, polydentate, and bicarbonates could be observed below 1800 cm –1 . , The formation of carbonate species progressed as the temperature increases for all catalysts, but higher Co content limited the extent of carbonate species formation.…”

“…Two vibration bands at approximately 2116 and 2175 cm −1 were observed for all catalysts at the lowest temperatures, corresponding to the P and R branches of gaseous CO, respectively. 36,56 Simultaneously, the progressive formation of CO 2 as a function of temperature can be observed for all catalysts by the intensity of the gas-phase CO 2 bands at 2360 and 2330 cm −1 . Moreover, several bands of symmetric and asymmetric vibrations attributed to different carbonate species, including monodentate, bidentate, bridged, polydentate, and bicarbonates could be observed below 1800 cm −1 .…”

Green Fabrication of Heterostructured CoTiO3/TiO2 Nanocatalysts for Efficient Photocatalytic Degradation of Cinnamic Acid

“…The citrate method is widely used in the preparation of many types of perovskites, for example, the catalytic oxide precursors MNiO x (M = La, Ce, and Sr) , and the La 1– x Ce x NiO 3 mixed oxides were prepared by the citrate method. A series of LaNiO 3 materials were synthesized by the ethylenediamine tetraacetic acid (EDTA)–citrate complexing method and citrate sol–gel method, , while ferroelectric LaNiO 3 powders were prepared using an “amorphous citrate” route . This method uses citric acid as a complexing agent and metallic nitrates as precursors.…”

Obtenção de hidrogênio pela reforma a vapor do glicerol residual do biodiesel utilizando catalisadores de Ni/La>sub<2>/sub<O>sub<3>/sub<- CeO>sub<2>/sub< /SiO>sub<2>/sub<

“…A partir dos resultados pode-se observar que o tamanho e volume de poro, bem como a área superficial específica das amostras não apresentaram grandes diferenças entre si e nem em relação à adição de surfactante. Os baixos valores obtidos são característicos desse tipo de material (GONZÁLEZ et. al., 2022).…”