Dry reforming of methane: thermodynamic, kinetic and catalyst coking investigations

This study investigates the performance of dry reforming of methane (DRM) using a novel bifunctional Fe/C catalyst within the framework of sustainable hydrogen and syngas production. DRM offers the dual benefit of converting two major greenhouse gases, CH 4 and CO 2 , into an equimolar mixture of H 2 and CO, suitable for Fischer-Tropsch synthesis and clean fuel production. Despite its potential, DRM is challenged by high endothermicity, catalyst coking leading to catalyst deactivation. This work combines thermodynamic and kinetic analyses to evaluate catalyst performance and process optimization. Gibbs free energy minimization was employed to determine equilibrium limits on conversion, product distribution, and carbon formation, highlighting the critical roles of temperature, pressure, and feed composition. Experimental studies using thermogravimetric analysis coupled with gas chromatography assessed kinetic behaviour, H 2 and CO formation rates, and catalyst coking. The Fe/C catalyst demonstrated significantly lower activation energies, superior CH 4 and CO 2 conversions, and improved H 2 and CO yields compared to the majority of catalysts. Catalyst coking was systematically studied, showing dependence on reactant partial pressures and temperature, with results aligning with thermodynamic predictions. • Thermodynamics impose limits on product distribution and carbon formation in DRM. • The bifunctional Fe/C catalyst offers advantageous compared to most literature catalysts. • The H 2 formation rate is highly sensitive to P C H 4 and largely independent of P C O 2 • The CO formation rate is strongly dependent to P C O 2 • TGA reveals effects of P C H 4 and P C O 2 , and temperature on Fe/C catalyst coking.