PdZnβ catalyst with low-Pd loading on ZnTiO3 perovskite for hightemperature methanol steam reforming

Abstract

PdZnβ alloy catalysts have attracted extensive attention in methanol steam reforming (MSR) reaction, due to their superior thermal ability compared to Cu-based catalysts, which are prone to sintering. However, conventional supported PdZn catalysts typically require a high Pd loading (e.g., Pd/ZnO, > 5.0 wt%) to achieve desired MSR performance, limiting their practical applications. In this work, we explore ZnTiO3 perovskite as a support and zinc source to achieve controlled synthesis of PdZnβ alloy at low Pd loadings. The 0.1 wt% Pd/ZnTiO3 catalyst achieved excellent reactivity and CO2 selectivity (> 96%) across a wide temperature range (up to 400°C), due to the enhanced synergy between the small PdZnβ particles and the ZnTiO3 support, which enhances methanol dehydrogenation and water dissociation respectively. The catalyst also showed exceptional thermal stability over 50 hours at 350°C with minimal loss in activity or selectivity, while pure ZnTiO3 deactivated significantly. The advanced Pd/ZnTiO3 catalysts with ultra-low Pd loading show greater potential compared to other metal oxides for efficient and stable hydrogen production in mobile applications, which typically require high reaction temperatures.