<p>The reduction of iron ore can be promoted and CO₂ emissions can be reduced by injecting hydrogen-rich fuel into blast furnaces; however, the deterioration of coke strength is caused by the CO₂ and H₂O generated. Therefore, this paper integrates thermodynamic and kinetic analyses to investigate the influence mechanisms of CO₂, H₂O, or H₂O–CO₂ mixed gas on the deterioration behavior of coke within a temperature range of 1173&#xa0;K to 1423&#xa0;K. Research results shows that the solution loss zone and the protection zone of coke during the co-gasification of H₂O and CO₂ have been identified based on thermodynamic analysis. The deterioration of coke by H₂O is greater than that by CO₂. When the H₂O/CO₂ ratio was 3:7, the experimental values of coke solution loss were found to almost align with the theoretical value of weight, indicating that there was no interaction between H₂O and CO₂ in the mixed gas. Simultaneously, microstructure analysis shows the theoretical values for the porosity at both the edge and center of the coke were closely aligned with the experimental values when H₂O/CO₂ = 3/7, which further confirmed that no interaction is generated between H₂O and CO₂. Kinetics analysis study shows that the unreacted shrinking core model is followed in the coke solution loss reaction, with the interfacial chemical reaction serving as the primary restrictive link. The activation energy for the reaction between coke and CO₂ is higher than that for the reaction between coke and H₂O, indicating that coke exhibits a greater propensity to react with H₂O than CO₂.</p> Graphical Abstract <p></p>