Styrene (ST) is commercially produced by the dehydrogenation of ethylbenzene (EB) on the promoted iron oxide catalysts at 600–700◦C, just below the temperature where thermal cracking becomes significant. Due to its highly endothermic and volume-increasing character, a large amount of superheated steam is used to supply heat, lower the partial pressure of the reactant, and avoid the formation of carbonaceous deposits. However, much of the latent heat of steam is lost in the gas–liquid separator without recovery [1]. The dehydrogenation of EB to ST in the presence of CO2 instead of steam is believed to be an energy-saving and environmentally friendly process. The equilibrium conversion can be improved through the reaction coupling of EB dehydrogenation with the reverse water–gas shift (RWGS) [2], and it is estimated that the energy required for producing per ton ST in the coupling process is (1.5–1.9) × 108 cal