La₂O₃‐Promoted Ni/Al₂O₃ Catalyst for CO Methanation: Enhanced Catalytic Activity and Stability

Abstract

To simultaneously inhibit Ni sintering and coke formation, while maintaining high catalytic activity, Ni–La2O3/Al2O3 catalysts are prepared by a modified deposition–precipitation (DP) method and applied for the CO methanation reaction. The activity of the catalyst prepared by the DP method is much higher than those prepared by the traditional impregnation and co‐impregnation methods due to the promotion of La2O3 as well as its unique dispersion on the surface of the catalyst. In the 100 h‐lifetime test under the conditions of 450 °C, 0.1 MPa, a weight hourly space velocity (WHSV) of 120 000 mL g−1 h−1, the Ni–La2O3/Al2O3 catalyst prepared by the DP method shows high catalytic stability. The characterization results show that La2O3 species can be deposited on the surface of the catalyst during the preparation process and can act as a physical barrier to prevent sintering of Ni particles and coke formation during high‐temperature reduction and reaction. La2O3 species can improve the reducibility of Ni particles and decrease the Ni particle sizes, resulting in larger H2 uptake and higher catalytic activity. Furthermore, the La3+/La2+ redox can also decrease coke formation by increasing the active oxygen species on the Ni surface.

Perovskite LaNiO3 Nanocrystals inside Mesostructured Cellular Foam Silica: High Catalytic Activity and Stability for CO2 Methanation

“…There are two diffraction peaks at 44.6° and 51.9°, attributing to (111) and (200) planes of metallic Ni (JCPDS No. 01‐070‐1849) on the XRD patterns of the reduced 10LNOM‐C‐650, 10LNOM‐C‐750, and 10LNOM‐C‐850 catalysts . The intensity of the crystal‐phase peak increases accordingly with the increase in LaNiO 3 loading (Figure c).…”

Sodium Tungstate Supported on a Three‐dimensional and Networked SBA‐15 for Knoevenagel Reaction

“…As seen, the wide spectrum in Figure a confirmed that the expected elements (Na, W, O, Si) were present in this catalyst. Among them, the spectrum of W 4 f showed two peaks at 35.60 and 37.75 eV corresponding to W 6+ (Figure c) …”

Synthesis of Catalytic Precursors Based on Mixed Ni-Al Oxides by Supercritical Antisolvent Co-Precipitation

“…The most common methods of Ni-Al 2 O 3 catalyst synthesis are impregnation [11], deposition-precipitation [12], and the sol-gel method [13]. The disadvantages of these synthesis methods are the use of toxic nitrates and the formation of wastewater, which require additional processing.…”