Promoting C-F Bond Activation for Perfluorinated Compounds Decomposition via Atomically Synergistic Lewis and
Wenjie Luo1,2, Kang Liu1,2, Tao Luo1,2,3
1Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physics, Central South University, Changsha 410083, Hunan, China.
Abstract:
Catalytic hydrolysis is a sustainable method for the degradation of perfluorinated compounds (PFCs) but is challenged by the high reaction temperatures required to cleave strong C-F bonds. Herein, we developed an innovative C-F activation strategy by constructing synergistic Lewis and Brønsted acid pairs over atomically dispersed Zn-O-Al sites to promote C-F bond activation for decomposition of typical PFCs, CF4. Density functional theory (DFT) calculations demonstrate tricoordinated Al (AlIII) sites and Zn-OH functional, respectively, as Lewis and Brønsted acid sites over Zn-O-Al, synergistically enhancing the adsorption and decomposition of CF4. X-ray absorption spectroscopy (XAS), pyridine infrared spectroscopy (Py-IR), and ammonia temperature-programmed desorption (NH3-TPD) verified the presence of both AlIII and Zn-OH on the atomically dispersed Zn-O-Al sites. CF4-TPD and in situ infrared spectroscopy confirmed that the Zn-O-Al sites facilitate CF4 adsorption and C-F bond activation. As a result, the Zn-O-Al sites with synergistic Lewis and Brønsted acid pairs achieved 100% CF4 decomposition at a low temperature of 560 °C and demonstrated outstanding stability for more than 250 h.
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