Unlocking High-Efficiency Methane Oxidation with Bimetallic Pd-Ce Catalysts under Zeolite Confinement

Xiaomai Chen; Xuefeng Shi; Peirong Chen; Bowen Liu; Meiyin Liu; Longwen Chen; Daiqi Ye; Xin Tu; Wei Fan; Junliang Wu

doi:10.1021/acsenvironau.3c00008

Unlocking High-Efficiency Methane Oxidation with Bimetallic Pd-Ce Catalysts under Zeolite Confinement

ACS Environ Au. 2023 May 16;3(4):223-232. doi: 10.1021/acsenvironau.3c00008. eCollection 2023 Jul 19.

Authors

Xiaomai Chen¹, Xuefeng Shi¹, Peirong Chen¹, Bowen Liu², Meiyin Liu¹, Longwen Chen³, Daiqi Ye¹, Xin Tu², Wei Fan⁴, Junliang Wu¹

Affiliations

¹ National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
² Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, U.K.
³ College of Light Chemical Industry and Materials Engineering, Shunde Polytechnic, Foshan 528333, China.
⁴ Department of Chemical Engineering, University of Massachusetts-Amherst, Amherst, Massachusetts 01003, United States.

Abstract

Catalytic complete oxidation is an efficient approach to reducing methane emissions, a significant contributor to global warming. This approach requires active catalysts that are highly resistant to sintering and water vapor. In this work, we demonstrate that Pd nanoparticles confined within silicalite-1 zeolites (Pd@S-1), fabricated using a facile in situ encapsulation strategy, are highly active and stable in catalyzing methane oxidation and are superior to those supported on the S-1 surface due to a confinement effect. The activity of the confined Pd catalysts was further improved by co-confining a suitable amount of Ce within the S-1 zeolite (PdCe_0.4@S-1), which is attributed to confinement-reinforced Pd-Ce interactions that promote the formation of oxygen vacancies and highly reactive oxygen species. Furthermore, the introduction of Ce improves the hydrophobicity of the S-1 zeolite and, by forming Pd-Ce mixed oxides, inhibits the transformation of the active PdO phase to inactive Pd(OH)₂ species. Overall, the bimetallic PdCe_0.4@S-1 catalyst delivers exceptional outstanding activity and durability in complete methane oxidation, even in the presence of water vapor. This study may provide new prospects for the rational design of high-performance and durable Pd catalysts for complete methane oxidation.