Investigating the role of potassium modification in the catalytic activity and stability of ZnO-activated carbon catalysts for methyl formate decomposition

Abstract

Methyl formate (MF) decomposition is essential for producing valuable chemicals, but finding efficient and stable catalysts is challenging. This study explores the catalytic performance of ZnO/AC, K8-10-4/AC, and Zn5K8-10-4/AC in MF decomposition. The catalysts were synthesized by varying the potassium-to-carbon ratios and the calcination temperatures and durations, and characterized using nitrogen adsorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), CO₂-TPD, and in-situ DRIFTS. Zn5K8-10-4/AC demonstrated significantly higher activity, with a conversion rate of 99.3%, compared to ZnO/AC (18.4%) and K8-10-4/AC (2.4%) at 210 °C. Potassium addition enhanced the basicity and surface properties, facilitating ester bond cleavage and HCOO species formation. Zn5K8-10-16/AC also exhibited excellent stability over 100 hours, in contrast to the rapid deactivation observed with K8-10-16/AC. This study highlights the synergistic effect of zinc and potassium for improving catalytic performance and stability, offering insights for designing more efficient catalysts for MF decomposition and similar reactions.