Pd/C catalysts containing reduced palladium nanoparticles on activated carbon were obtained by pyrolysis of wood sawdust impregnated sequentially or simultaneously with phosphoric acid and palladium nitrate. Low-temperature nitrogen adsorption-desorption, scanning electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy methods show that pyrolysis leads to the formation of microporous carbon material with high content of graphite-like carbon and high specific surface area (1600-1900 m/g) regardless of the acid treatment conditions. According to X-ray photoelectron spectroscopy and transmission electron microscopy, the obtained Pd/C catalysts include predominantly nanosize Pd particles. Co-impregnation with phosphoric acid and palladium nitrate provides catalyst with larger average palladium particle size, higher surface palladium content and increased activity and stability in gas-phase hydrodechlorination of chlorobenzene in comparison to catalyst obtained by sequential impregnation with phosphoric acid and palladium nitrate and characterized by slightly higher fraction of reduced palladium.
S.V. Klokov (Wed,) studied this question.