Impacts of nickel loading on properties, catalytic behaviors of Ni/γ–Al2O3 catalysts and the reaction intermediates formed in methanation of CO2

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

“…Overall, there are two separate desorption peaks with varied intensities for all the catalysts. The low‐temperature peak at around 173 °C is attributed to the chemisorbed hydrogen on the highly dispersed Ni nanoparticles, which has a higher number of defect sites and can serve as a capture center for surface hydrogen, thereby reducing the activation energy of H 2 dissociation. The high‐temperature peak at around 367 °C is attributed to the adsorption of hydrogen on the surface of bulk Ni particles.…”

“…The high‐temperature peak at around 367 °C is attributed to the adsorption of hydrogen on the surface of bulk Ni particles. Compared with 20NA, the integral area of H 2 ‐TPD curves of 20NA x L increases significantly, especially for desorption peaks at around 173 °C, indicating that more active sites are obtained over 20NA x L. The H 2 uptakes and Ni dispersion of the catalysts were calculated and listed in Table . Apparently, doping proper amount of La 2 O 3 on 20NA by the DP method can significantly increase the hydrogen adsorption capacity of the 20NA x L catalyst, and 20NA1L shows the highest H 2 uptake of 213.09 μmol g −1 and Ni dispersion of 15.93%.…”

“…The Ni/Al 2 O 3 catalyst was prepared by the traditional wet impregnation method . Typically, 1.45 g of Ni(NO 3 ) 2 ·6H 2 O was dissolved in 30 mL ethanol, followed by the addition of 2.00 g of Al 2 O 3 support to form a slurry, which was vigorously stirred at room temperature overnight and then heated to evaporate the liquid, dried at 100 °C for 24 h, and further calcined at 400 °C for 2 h in air at the heating rate of 5 °C min −1 .…”

“…La 2 O 3 was used as the promoter in the Ni/Al 2 O 3 catalyst for CO 2 methanation reaction, which enhanced the basicity of the catalyst, strengthened the metal–support interaction, and cleaned the deposited carbon, resulting in the suppression of carbon deposition and the improvement of stability . In addition, La 2 O 3 can effectively restrain the growth of NiO nanoparticles and improve the dispersion of active species over support, resulting in enhanced catalytic activity . Hence, it is proposed that La 2 O 3 can also be an efficient promoter for the Ni/Al 2 O 3 catalyst for CO methanation.…”

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

“…For methanation reaction, nickel loading is crucial for the catalytic activity due to its amount of available active sites, which is the reason why Ni loadings are usually high for industrial catalysts . In addition, reducing Ni particle size and addition of proper promoters are two efficient strategies to improve the catalytic performance for CO 2 methanation .…”