Impact of K on the Basicity and Selectivity of Pt/m-ZrO2 Catalysts for Methanol Steam Reforming with co-fed H2

This study investigates the effect of potassium (K) promotion on Pt/m-ZrO2 catalysts in methanol steam reforming (MSR), revealing critical insights into reaction pathways and catalyst performance. While increasing K loading reduces catalytic activity, it selectively enhances the hydrogen-producing formate dehydrogenation and de-carboxylation pathway. Structural analyses using HR-TEM and DRIFTS show that higher K concentrations block Pt sites and promote agglomeration, reshaping catalytic behavior. Notably, the 3.1% K-promoted catalyst achieves high stability at 358 °C, with a CO2 selectivity exceeding 80% and minimal methane formation, outperforming the unpromoted catalyst in terms of CO and CH4 selectivity. Temperature studies further demonstrate reduced CO selectivity at higher temperatures, highlighting distinct advantages of K-doped catalysts. These findings underscore the role of K in enhancing surface basicity and its impact on formate interaction, offering valuable insights for optimizing MSR catalysts and advancing hydrogen production technologies.