Reducing Agent-Structure-Activity Relationship of PdAg/C Catalysts in Formic Acid Decomposition for Hydrogen Generation

The reducing agent effect on surface structure and then catalytic activity towards formic acid decomposition for hydrogen generation of PdAg/C nanoparticles was investigated. The PdAg/C catalysts were prepared by four different reducing agents including formic acid, hydrogen, sodium borohydride and ascorbic acid. X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy were used to evaluate the physical structure of PdAg nanoparticles. It was found that reducing agents affected degree of alloying, particle size, atoms distribution and electronic state of the PdAg surface. The combination of structure with activity results indicated that the abundant and electron-rich Pd atoms benefited the catalytic activity. The PdAg/C catalyst prepared by using formic acid as a reducing agent showed high selectivity, high durability and the highest initial turnover frequency of 90 h(-1) for hydrogen generation from formic acid decomposition without any additive at room temperature.