Elucidating the hydrogen mitigation mechanism of platinum-titanium mesh: Experimental and theoretical study of catalytic hydrogen–oxygen recombination

Mastering the reaction kinetics and mechanism of hydrogen-mitigation catalysts is key to predicting hydrogen mitigation performance. Here, a 15.625 L cubic sealed container is used to investigate the reaction characteristics and kinetic parameters of electroplated platinum-titanium mesh (Pt/Ti-mesh) catalysts (4 (Formula presented) m plating) in both single-plate and parallel-array configurations. Results indicate that reaction temperature rise increases with initial hydrogen concentration. In the single-plate configuration, temperature rise initially increases and then declines along the height, with significantly higher bottom temperature rise than the parallel-array configuration. The parallel-array configuration shows a gradual decrease in temperature rise along the height, featuring asymmetric internal plate temperature distribution and lower average temperature rise. Activation energies are 16.07 kJ/mol (single-plate) and 12.55 kJ/mol (parallel-array) with pre-exponential factors of 0.68 and 0.84, respectively, within literature-typical ranges. The hydrogen mitigation mechanism of Pt/Ti-mesh aligns with the Langmuir-Hinshelwood principle, where hydrogen and oxygen undergo dual dissociative adsorption on Pt surfaces.