Promoting CF bond activation by Ce/Al2O3 catalyst for CF4 plasma-catalytic decomposition

Tetrafluoromethane (CF 4 ), a highly potent greenhouse gas characterized by the notable capacity to absorb infrared radiation, making its effective control essential for mitigating global warming. However, the activation of CF 4 faces challenges in the conventional approaches caused by its symmetric structure and strong C F bonds. In this work, we presented an approach to enhance the activation of C F bonds using an inductance-enhanced Ce/Al 2 O 3 catalyst within the designed plasma-catalytic reaction system featuring a step-discharge effect. The optimal CF 4 decomposition efficiency reached approximately 89.5 % at the power of 18 W, while maintaining above 88.6 % for 24 h. The impact of plasma conditions and flue gas parameters on CF 4 decomposition and energy efficiency was also investigated. Py-IR showed that the Ce/Al 2 O 3 catalyst provided more Lewis acid sites as the active centers for breaking C F bonds. In situ FTIR and in situ OES studies revealed that the intermediates generated from CF 4 decomposition can react with active oxygen to form C O bond under the plasma-catalytic effect, preventing the reformation of C F bonds. DFT calculations demonstrated that the Ce/Al 2 O 3 exhibited a lower energy barrier to dissociate CF 4 and a stronger adsorption for O 2 . This work established a novel pathway for the activation of C F bonds to achieve the efficient decomposition of CF 4 at low temperatures.