Design of Ni‐substituted La2(CeZrNi)2O7 Pyrochlore Catalysts for Methane Dry Reforming. Issue 3 (27th January 2022)

• Record Type: Journal Article
• Authors: Bai, Jieru; Fu, Yu; Kong, Wenbo; Pan, Bingrong; Yuan, Changkun; Li, Shuqing; Wang, Jiyang; Zhang, Jun; Sun, Yuhan
• Is Part Of: ChemNanoMat. Volume 8:Issue 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-27
• Subjects: catalyst -- deactivation -- oxygen vacancy -- pyrochlore; Nanochemistry -- Periodicals; Nanostructured materials -- Periodicals; Nanochemistry; Nanostructured materials; Periodicals; 541.2
• DOI: 10.1002/cnma.202100422
• Languages: English
• ISSNs: 2199-692X

Abstract

Abstract: Ni‐based catalysts for dry reforming of methane (DRM) are prone to suffer from deactivation caused by carbon deposition and sintering. Pyrochlore (typically A2 B2 O7 ) is a thermostable material with substantial redox capacity, which makes it suitable as a support for Ni‐based DRM catalysts. Here we demonstrated that by adjusting the Zr/Ce ratio in the B‐site of the La2 (CeZrNi)2 O7 (10 wt.% Ni loading), its structural order could be significantly altered. With decreasing Zr/Ce ratio, the structure of the catalysts became less ordered with a phase transformation from pyrochlore (La2 Zr2 O7 ) to defective fluorite (La2 Ce2 O7 ). Meanwhile, a second phase La2 NiZrO6 /LaNiO3 other than pyrochlore was formed for each sample. By tuning the structure, samples presented different properties and XPS results illustrated that the compositions of the surface oxygen species of samples were significantly different. Catalysts possessing more oxygen vacancies displayed evidently enhanced coke resistance. Among all five catalysts, LNZ3C1 exhibited the highest activity, stability and carbon deposition resistance, which could be attributed to the most oxygen vacancies, the strongest nickel‐carrier interaction, and the best particle size distribution of it. Abstract : The La2 (CeZrNi)2 O7 pyrochlore catalysts with different Zr/Ce ratio in the B‐site present different properties due to the phase transition and.Ni substitution‐exsolution, thus resulting in the catalyst with Zr/Ce ratio of 3 : 1 showing improved catalytic activity and outstanding stability for DRM reaction.