Bendieb Aberkane Amar, Yeste María Pilar, Djazi Fayçal, Cauqui Miguel Ángel
Laboratoire de Recherche sur la Physico-Chimie des Surfaces et Interfaces (LRPCSI), Faculté de Technologie, Département de Génie des Procédés, Université 20 Août 1955-Skikda, BP 26, Route d'El Hadaiek, Skikda 21000, Algeria.
Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Universidad de Cádiz, Campus Río San Pedro s/n, 11510 Cádiz, Spain.
Nanomaterials (Basel). 2022 Jul 30;12(15):2627. doi: 10.3390/nano12152627.
In this study, a series of NiO-CeO mixed-oxide catalysts have been prepared by a modified co-precipitation method similar to the one used for the synthesis of hydrotalcites. The syntheses were carried out at different pH values (8, 9 and 10), in order to determine the influence of this synthetic variable on the properties of the obtained materials. These materials were characterized by using different techniques, such as TGA, XRD, ICP, N adsorption-desorption isotherms, H temperature-programmed reduction (H-TPR), and electron microscopy, including high-angle annular dark-field transmission electron microscopy (HAADF-TEM) and EDS. The characterization results revealed the influence of the preparation method, in general, and of the pH value, in particular, on the textural properties of the oxides, as well as on the dispersion of the Ni species. The catalyst prepared at a higher pH value (pH = 10) was the one that exhibited better behavior in the CO methanation reaction (almost 100% CO conversion at 235 °C), which is attributed to the achievement, under these synthetic conditions, of a combination of properties (metal dispersion, specific surface area, porosity) more suitable for the reaction.
在本研究中，通过一种类似于用于合成水滑石的改进共沉淀法制备了一系列NiO-CeO混合氧化物催化剂。合成在不同的pH值（8、9和10）下进行，以确定该合成变量对所得材料性能的影响。这些材料使用不同的技术进行表征，如热重分析（TGA）、X射线衍射（XRD）、电感耦合等离子体（ICP）、N吸附-脱附等温线、H程序升温还原（H-TPR）以及电子显微镜，包括高角度环形暗场透射电子显微镜（HAADF-TEM）和能谱分析（EDS）。表征结果揭示了一般制备方法，特别是pH值对氧化物的织构性质以及Ni物种分散性的影响。在较高pH值（pH = 10）下制备的催化剂在CO甲烷化反应中表现出更好的性能（在235°C时CO转化率几乎达到100%），这归因于在这些合成条件下实现了更适合该反应的性能组合（金属分散性、比表面积、孔隙率）。
