Synergistic tuning of the phase structure of alumina and ceria-zirconia in supported palladium catalysts for enhanced methane combustion. (28th September 2021)

• Record Type: Journal Article
• Authors: Lin, Jia; Chen, Yelin; Huang, Jiangli; Cai, Guohui; Xiao, Yihong; Zhan, Yingying; Zheng, Ying
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 67(2021)
• Page Start: 33397
• Page End: 33408
• Publication Date: 2021-09-28
• Subjects: Methane combustion -- Pd-based catalysts -- CeO2–ZrO2–Al2O3 composite oxides -- Phase structure -- Surface property; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.07.151
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: CeO2 –ZrO2 –Al2 O3 composite oxides supported palladium catalysts (Pd/CZA) are promising candidates for catalytic oxidation reactions. However, the efficient and stable oxidation of methane over Pd-based catalysts remains a longstanding challenge. Herein, we present a facile strategy to boost the catalytic performance of Pd/CZA through elaborately tuning the phase structure of supports. Calcining supports at relatively high temperatures (1200, 1300 °C) induced the phase transition of alumina (from γ-to α-) and the development of CeO2 –ZrO2 solid solution (CZ). The weak interaction between α-Al2 O3 and PdO resulted in an improved reducibility of catalysts. Meanwhile, the higher oxygen mobility originated from well-crystallized CZ phase contributed to the reoxidation of Pd to PdO, giving rise to abundant surface active Pd 2+ species. Coupled with the hydrophobicity of α-Al2 O3, the catalyst prepared with CZA supports calcined at 1300 °C demonstrated an excellent low-temperature activity, astounding stability and greatly enhanced water resistance towards methane combustion. Graphical abstract: Image 1 Highlights: Phase structure of Ce–Zr–Al supports was tuned with calcination temperature. α-Al2 O3 phase gave rise to an improved reducibility and water-resistance. Well-crystallized Ce–Zr solid solution phase contributed to the reoxidation of Pd 0 . Synergy of α-Al2 O3 and Ce–Zr solid solution invoked a high-performance of Pd/CZA.