Dual-Site Synergistic C–F Bond Activation over Fe 1 /Al 2 O 3 for Efficient CF 4 Decomposition

Alumina (Al 2 O 3 )-based catalysts are widely used for the catalytic hydrolysis of CF 4, where coordinatively unsaturated Al (Al III ) sites cooperate with surface hydroxyl groups to facilitate C–F bond activation. However, the catalytic performance of conventional Al 2 O 3 is strongly limited by the low abundance of Al III sites and the insufficient reactivity of hydroxyl species, making high temperatures necessary for complete CF 4 conversion. In this study, we report a single-atom Fe modification strategy (Fe 1 /Al 2 O 3 ) that promotes CF 4 hydrolysis by simultaneously increasing the fraction of Al III sites and enhancing the Brønsted acidity of surface hydroxyl groups. 27 Al magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy showed that the incorporation of isolated Fe atoms increased the proportion of Al III sites from 2.1% to 9.9%, corresponding to a 4.7-fold enhancement. Pyridine-IR (Py-IR) results further indicated that the Brønsted acidity associated with surface −OH species on Fe 1 /Al 2 O 3 was 5.4 times higher than that of pristine Al 2 O 3 . In addition, temperature-programmed desorption (TPD) and in situ infrared spectroscopy revealed much stronger CF 4 adsorption and C–F bond activation ability over Fe 1 /Al 2 O 3 . Consequently, Fe 1 /Al 2 O 3 delivered complete CF 4 decomposition at 580 °C and maintained stable performance for more than 200 h, whereas pure Al 2 O 3 only achieved 56% conversion and remained stable for 30 h. These findings provide a viable strategy for the rational design of highly active catalysts for low-temperature CF 4 hydrolysis.