Abstract Cobalt and nickel-based catalysts were synthesized by the co-impregnation method of the ceria support with aqueous solution of the active phase and promoter precursors and evaluated in steam reforming of ethanol (SRE) reaction. The stability of Co/CeO2 and Ni/CeO2 catalysts was effectively improved by the addition of ∼2 wt% of La2O3 promoter as the carbon deposition rate was reduced which results from an increase in an active phase dispersion and from strengthening of a metal-support interactions. Whereas the La2O3 promoter influences on the rate of carbon deposit formation, its type and a degree of graphitization depends on the metal active phase. Highly ordered carbon deposit encapsulating the active sites was mainly formed on the surface of cobalt-based catalysts. Whereas SRE reaction over nickel-based catalysts leads to formation of long filaments carbon with a lower degree graphitization. Temperature of 460 °C was sufficient to obtain complete ethanol conversion for 21 h of SRE process over Ni-0.1La/CeO2 sample and to maintain high selectivity to H2 (88%) and CO2 (68%) over this time. For Co-0.1La/CeO2 catalyst, the higher temperature of 500 °C was required to sustain its stable operation but selectivity to H2 and CO2 was even higher, 94% and 88%, respectively.

中文翻译：

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提高 La2O3 促进 Co/CeO2 和 Ni/CeO2 催化剂的催化性能，以通过乙醇蒸汽重整有效制氢

摘要 采用氧化铈载体与活性相水溶液和助催化剂前驱体的共浸渍法合成了钴镍基催化剂，并在乙醇蒸汽重整（SRE）反应中进行了评价。Co/CeO2 和 Ni/CeO2 催化剂的稳定性通过添加~2wt%的 La2O3 促进剂有效提高，因为碳沉积速率降低，这是由于活性相分散的增加和金属载体的增强相互作用。尽管 La2O3 促进剂会影响积碳的形成速度，但其类型和石墨化程度取决于金属活性相。包裹活性位点的高度有序的碳沉积主要形成在钴基催化剂的表面。而镍基催化剂上的 SRE 反应导致形成石墨化程度较低的长丝碳。460 °C 的温度足以在 Ni-0.1La/CeO2 样品的 SRE 过程中获得 21 小时的完全乙醇转化，并在此期间保持对 H2 (88%) 和 CO2 (68%) 的高选择性。对于 Co-0.1La/CeO2 催化剂，需要 500 °C 的高温才能维持其稳定运行，但对 H2 和 CO2 的选择性甚至更高，分别为 94% 和 88%。