Construction of the Low-Loading Ni/CeO₂ Catalyst with a Boosted CO₂ Methanation Performance via the Facile Pyrolysis CeO₂ Support

Abstract

Ni-loaded CeO 2 -based materials are one type of the promising catalyst for CO 2 methanation; however, lowering the Ni loading, simplifying the preparation process of CeO 2 supports, and improving the low-temperature catalytic performance are always essential for scalable applications. Herein, an efficient CeO 2 support (CeO 2 -NC) with a large inner pore size was prepared by a facilely controlled calcination of cerium nitrate [Ce(NO 3 ) 3 •6H 2 O] method. On the basis of CeO 2 -NC, one catalyst (Ni/CeO 2 -NC) with low Ni loading (2.56 wt %), desirable Ni dispersity, and abundant medium basic sites was developed that exhibited the amazing low-temperature CO 2 methanation performance. At 275 °C, CO 2 conversion reached up to 77.7% with an almost 100% CH 4 selectivity under a high gas hourly space velocity of 60000 mL g cat −1 h −1 , and the Ni-based mass-specific CH 4 formation rate at 300 °C was up to 4740 μmol g Ni −1 s −1 , outperforming most of the reported Ni-based catalysts to date. The in situ diffuse-reflectance infrared Fourier transform spectroscopy experiments revealed that plentiful active bidentate carbonate intermediates and effective suppression of the dissociated active H species recombination contributed to the boosted CO 2 methanation performance of Ni/CeO 2 -NC at low temperatures. Moreover, the mechanism was also inferred. This work provides new insight into simple pyrolysis CeO 2 supports and should be of significance for the rational design of highly efficient CO 2 methanation catalysts.

Oxidation of Toluene over Mesoporous MnO2/CeO2 Nanosphere Catalysts: Effects of the MnO2 Precursor and the Type of Support

“…Raman characterization was performed in the scan range of 200–1200 cm –1 over MS-CeO 2 and 15MnO 2 /MS-CeO 2 to further analyze the local structural distortion of the catalysts. It can be observed from Figure that the MS-CeO 2 support and its supported catalysts with different precursors displayed one prominent vibrational peak at 450 cm –1 and one weaker peak at 620 cm –1 , which were attributed to the strong Raman-activated F 2g vibrational mode of the CeO 2 lattice and the defect-induced (D) mode, respectively . It was found that the relative intensity I (D) / I (F2g) ratio of the 15MnO 2 /MS-CeO 2 -N catalyst (0.48) was slightly higher than that of MS-CeO 2 (0.27), 15MnO 2 /MS-CeO 2 -S (0.15), 15MnO 2 /MS-CeO 2 -Cl (0.38), and 15MnO 2 /MS-CeO 2 -AC (0.27).…”

“…with different precursors displayed one prominent vibrational peak at 450 cm −1 and one weaker peak at 620 cm −1 , which were attributed to the strong Raman-activated F 2g vibrational mode of the CeO 2 lattice and the defect-induced (D) mode, respectively. 52 It was found that the relative intensity I (D) /I (F2g) ratio of the 15MnO 2 /MS-CeO 2 -N catalyst (0.48) was slightly higher than that of MS-CeO 2 (0.27), 15MnO 2 /MS-CeO 2 -S (0.15), 15MnO 2 /MS-CeO 2 -Cl (0.38), and 15MnO 2 /MS-CeO 2 -AC (0.27). This suggested that more intrinsic defect sites were generated in the CeO 2 lattice of the 15MnO 2 /MS-CeO 2 -N catalyst.…”

Research Progress of Non-Noble Metal Catalysts for Carbon Dioxide Methanation

“…CeO 2 has a high specific surface area and abundant oxygen vacancy [ 77 ]. Bian et al [ 78 ] prepared Ni-based catalysts with different CeO 2 morphologies by the hydrothermal method, namely 5Ni/NPs, 5Ni/NOs, 5Ni/NCs, and 5Ni/NRs.…”

“…However, a large amount of Ti 3+ will be produced after pretreatment of a-TiO 2 with NH 3 and H 2 , which can hinder the formation of titanium coating and change SMSI, so that the reactants can be exposed to more Ni species and enhance the catalytic activity of Ni/a-TiO 2 . CeO 2 has a high specific surface area and abundant oxygen vacancy [77]. Bian et al [78] prepared Ni-based catalysts with different CeO 2 morphologies by the hydrothermal method, namely 5Ni/NPs, 5Ni/NOs, 5Ni/NCs, and 5Ni/NRs.…”

“…Due to the insertion of Ni into the ZrO2 lattice and its own defects, oxygen vacancy was generated, which improved the adsorption and dissociation of CO on the Ni/ZrO2 catalyst. CeO2 has a high specific surface area and abundant oxygen vacancy [77]. Bian et al [78] prepared Ni-based catalysts with different CeO2 morphologies by the hydrothermal method, namely 5Ni/NPs, 5Ni/NOs, 5Ni/NCs, and 5Ni/NRs.…”