| Summary: | Greenhouse gases emitted by the aluminum electrolysis industry have brought great challenges to environmental protection. To address this problem, understanding the micro-generation mechanism of greenhouse gases in the electrolysis process is of great significance to their source suppression. Based on the first principles calculation method, the formation paths of CO, CO<sub>2</sub> and COF<sub>2</sub> during normal electrolysis were obtained by studying the adsorption behavior of oxygen and fluorine complex anions (short for [O]<sup>2−</sup>, [F]<sup>−</sup>) on the anode surface in cryolite alumina molten salt. The calculation results indicate that the O and F atoms prefer to adsorb at bridge site 1 of Model A, with the adsorption energies of −4.82 eV and −3.33 eV. In the [O]<sup>2−</sup> priority discharge stage, Path 3 is the most likely path for CO<sub>2</sub> generation, while in the [O]<sup>2−</sup>, [F]<sup>−</sup> co-discharge stage, Path 3 is the most likely path for COF<sub>2</sub> generation. It is deduced that the thermal decomposition of COF<sub>2</sub> at high temperature should account for the generation of CF<sub>4</sub> with a low concentration of the so-called non-anode effect PFC (NAE-PFC). Experiments were also conducted to verify the calculation by disclosing the bonding information of C, O and F, which are in good accordance with the results calculated by the first principle.
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