An exsolved Cu nanocatalyst for highly efficient methanol steam reforming

BaZr0.1Ce0.7Y0.2O3 (BZCY) perovskite with in-situ exsolved metallic Cu catalyst acted as a catalyst for methanol steam reforming (MSR) for the first time. After reduction at 550 degrees C for 3 hours, fine and uniform metallic Cu nanoparticles were exsolved from the perovskite lattice with more active sites and oxygen vacancies on the surface. The reduced Ba0.9Zr0.1Ce0.7Y0.1Cu0.1O3 (BZCYCu) displayed a stable conversion of methanol above 99.9 % at 500 degrees C within 120 hours, with a negligible amount of CO in the outlet gas and no carbon species was detected on the surface of catalyst. The BZCYCu gained 7.4 % of their weight at 500 degrees C during the water vapor adsorption stage in temperature programmed water absorption experiment, which showed a considerable water adsorption capacity. Such a hygroscopicity could promote the catalytic methanol steam reforming and CO elimination. And metallic Cu has also been widely applied for the methanol steam reforming reaction due to their high activity and carbon resistance. The synergy of metallic Cu nanoparticles and perovskite substrate with more oxygen vacancies and well hydroscopicity improved the structural stability and ensured the catalytic activity of RBZCYCu catalysts. A Cu doped BaCeO3-type perovskite with Cu exsolution (RBZCYCu) was first evaluated for MSR and the composite catalyst displayed excellent catalytic performance with a stable conversion above 99.9 % within 120 hours. The BZCY perovskite substrate displayed an excellent water adsorption capacity and the synergy of Cu nanoparticles (NPs) and perovskite substrate ensured the catalytic activity.image