The Importance of Si─ONa─Al Moieties in Fe/ZSM‐5 Zeolite Catalysts for Selective Oxidation of Methane to Acetic Acid
Abstract
AbstractSelective oxidation of methane to acetic acid with high activity and selectivity remains a significant challenge. Brønsted acid sites (Si─OH─Al) are well‐known for their crucial role in facilitating methane oxidation to acetic acid over zeolite‐based catalysts. Here, we reported that Fe/ZSM‐5‐0.25Na with abundant Si─ONa─Al moieties outperformed Fe/ZSM‐5 (rich in Brønsted acid sites) in methane oxidation to acetic acid using H2O2 in the presence of CO. The Fe/ZSM‐5‐0.25Na yielded 144.1 µmol of oxygenated products, achieving an acetic acid selectivity of 81.8% at 50 °C for 2.0 h. These results surpass the performance of the Fe/ZSM‐5 catalyst, which produced 131.4 µmol of oxygenated products with an acetic acid selectivity of 58.4%. Spectroscopic characterizations and mechanistic studies revealed that the Si─ONa─Al moieties in Fe/ZSM‐5‐0.25Na facilitated electron donation to iron species, forming electron‐rich iron sites. These electron‐rich iron species promoted CO insertion and enhanced the formation of acetic acid through carbon–carbon coupling of methane and CO.
Article Details
Authors (9)
Xinyu Zhao
Haibin Yin
Hefei National Research Center for Physical Sciences at the Microscale Key Laboratory of Strongly‐Coupled Quantum Matter Physics of Chinese Academy of Sciences Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes Department of Chemical Physics University of Science and Technology of China Hefei Anhui 230026 P.R. China
Hongfei Lin
Hefei National Research Center for Physical Sciences at the Microscale Key Laboratory of Strongly‐Coupled Quantum Matter Physics of Chinese Academy of Sciences Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes Department of Chemical Physics University of Science and Technology of China Hefei Anhui 230026 P.R. China
Zijin Dai
Hefei National Research Center for Physical Sciences at the Microscale Key Laboratory of Strongly‐Coupled Quantum Matter Physics of Chinese Academy of Sciences Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes Department of Chemical Physics University of Science and Technology of China Hefei Anhui 230026 P.R. China
Xin Chen
Wenlong Wu
School of Chemistry & Chemical Engineering
Hongliang Li
Hefei National Research Center for Physical Sciences at the Microscale
Bo Wu
Jie Zeng
School of Chemistry & Chemical Engineering