Decoupling kinetic promotion and surface inhibition in perhydro‐dibenzyltoluene dehydrogenation on Fe ‐modified Pt/Al _{2 Li Yu, Haoyang Tu, Zhongyao Zhang, Ping Li}

Abstract

Perhydro‐dibenzyltoluene (H18‐DBT) is a safe and practical liquid organic hydrogen carrier for hydrogen storage and transportation. However, its dehydrogenation mechanism remains unclear and the H ₂ release rate is still limited. Here, the effects of Fe incorporation on H18‐DBT dehydrogenation over Pt/Al ₂ O ₃ were investigated through detailed kinetic analysis. Fe modified the electronic environment and accessibility of Pt sites without significantly affecting the Al ₂ O ₃ porous structure. A Langmuir–Hinshelwood model accounting for H18‐DBT adsorption, dehydrogenation, and inhibition by strongly bound intermediates described the reaction rates. Fe decreased the apparent activation energy of the kinetically relevant step from approximately 113 to 11–15 kJ mol ⁻¹ . However, increasing Fe content strengthened temperature‐dependent surface inhibition by stabilizing inhibitory intermediates that blocked Pt sites. Therefore, Pt‐Fe catalyst performance reflects a balance between kinetic promotion and surface inhibition. These findings provide mechanistic guidance for balancing promotion and inhibition in Pt‐Fe catalyst design.