Boosting methylcyclohexane dehydrogenation over Pt-based structured catalysts by internal electric heating

Methylcyclohexane (MCH) serves as an ideal hydrogen carrier in hydrogen storage and transportation process. In the continuous production of hydrogen from MCH dehydrogenation, the rational design of energy-efficient catalytic way with good performance remains an enormous challenge. Herein, an internal electric heating (IEH) assisted mode was designed and proposed by the directly electrical-driven catalyst using the resistive heating effect. The Pt/Al₂O₃ on Fe foam (Pt/Al₂O₃/FF) with unique three-dimensional network structure was constructed. The catalysts were studied in a comprehensive way including X-ray diffraction (XRD), scanning electron microscopy (SEM)-mapping, in situ extended X-ray absorption fine structure (EXAFS), and in situ CO-Fourier transform infrared (FTIR) measurements. It was found that the hydrogen evolution rate in IEH mode can reach up to above 2060 mmol·g_Pt⁻¹·min⁻¹, which is 2–5 times higher than that of reported Pt based catalysts under similar reaction conditions in conventional heating (CH) mode. In combination with measurements from high-resolution infrared thermometer, the equations of heat transfer rate, and reaction heat analysis results, the Pt/Al₂O₃/FF not only has high mass and heat transfer ability to promote catalytic performance, but also behaves as the heating component with a low thermal resistance and heat capacity offering a fast temperature response in IEH mode. In addition, the chemical adsorption and activation of MCH molecules can be efficiently facilitated by IEH mode, proved by the operando MCH-FTIR results. Therefore, the as-developed IEH mode can efficiently reduce the heat and mass transfer limitations and prominently boost the dehydrogenation performance, which has a broad application potential in hydrogen storage and other catalytic reaction processes.