Microkinetic Modeling of Cobalt-Support Interactions during Periodic Transient CO Hydrogenation

High Resolution Image Download MS PowerPoint Slide Renewable energy supply systems need storage concepts for times with low energy production. The CO hydrogenation toward CH 4 and other hydrocarbons is a promising approach for long-term chemical storage of renewable energy. However, reaction kinetics and mechanisms are still under debate, especially possible metal–support interactions. We applied the periodic transient kinetics method to the CO hydrogenation on two cobalt-based catalyst materials with identical Co particle sizes and different support materials, SiO 2 and TiO 2 . A lumped microkinetic model was developed for model-based evaluation of experimental results. It was revealed that the different carbon species present on the catalyst surface during the reaction apparently correspond to different reaction pathways. These pathways occur to a different extent, depending on the support material. Metal–support interactions between Co and TiO 2 increase the CO adsorption strength, leading to both a lower overall activity and a higher selectivity toward C 2+ hydrocarbons. The comparison between experimental measurements and simulation results shows the necessity to consider adsorption on the support material in order to reflect the observed oxygen and water dynamics.