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A thermodynamic study on a toluene chemical looping reforming process with six metal oxides was conducted to evaluate the product distribution for selecting an appropriate oxygen carrier with thermodynamic favorability towards high syngas yield. The results show that a suitable operation temperature for most oxygen carriers is 900 °C considering syngas selectivity and solid C formation whether the toluene is fed alone or together with fuel gas. The syngas selectivity of all oxygen carriers decreases with the increasing equivalence ratio, but the decrease degrees are quite different due to their different thermodynamic natures. With the increasing amounts of H₂ and CO, the syngas selectivity for various oxygen carriers correspondingly decreases. The addition of CO₂ and H₂O_(g) benefits reducing the solid C formation, whereas the addition of CH₄ leads to more solid C being produced. Under the simulated gasification gas atmosphere, a synergetic elimination of solid C and water–gas shift reactions are observed. In terms of syngas selectivity, Mn₂O₃ possesses the best performance, followed by CaFe₂O₄ and Fe₂O₃, but NiO and CuO exhibit the lowest performance. BaFe₂O₄ presents a high H₂ selectivity but a very poor CO selectivity due to the formation of BaCO₃, which has a high thermodynamic stability below 1200 °C. Nevertheless, Mn₂O₃ is more likely to form solid C than feeding toluene alone and has a lower melting point. Considering syngas selectivity, carbon deposit and melting point, CaFe₂O₄ exhibits the highest performance concerning the tar chemical looping.