Electric Field-Coupled CuZnAlCe Oxide Catalysts for Low-Temperature Methanol Decomposition to Hydrogen

A silicon carbide （SiC）-mixed， cerium （Ce）-modified copper–zinc–aluminum composite oxide catalyst （CuZn_0.5Al_0.2Ce-x） was prepared via the coprecipitation method. Its performance and enhancement mechanism for methanol decomposition to hydrogen under an electric field were investigated. The results demonstrate that the electric field directly drives efficient low-temperature methanol decomposition， reducing the reaction temperature from 300 ℃ under thermal conditions to below 155 ℃ with a conversion rate greater than 90%. Among the samples， the catalyst with a Ce/Cu molar ratio of 0.05 exhibited the highest activity， achieving a 50% methanol conversion rate at a bed temperature of 65 ℃， and reaching 100% conversion at 105 ℃ under a current of 300 mA. The effects of Ce doping on the microstructure and catalytic performance under the electric field were analyzed using X-ray diffraction （XRD）， X-ray photoelectron spectroscopy（XPS）， H₂-temperature-programmed reduction （H₂-TPR）， and transmission electron microscopy （TEM）. The results indicate that an appropriate amount of Ce effectively improves the dispersion of the active copper （Cu） phase and facilitates the formation of an efficient Cu–Ce electron transfer interface. Under the reducing effect of the electric field， a higher density of Cu⁰ sites and Ce³⁺ unsaturated sites are generated on the catalyst surface. These sites together constitute and maintain highly active “Ce³⁺–Cu⁰” centers， which synergistically enhance the low-temperature methanol decomposition performance.