Abstract
The chemical composition and morphology of the surface of silver crystals used as catalysts of oxidative dehydrogenation of ethylene glycol to glyoxal were studied. The crystals were prepared by electrolysis from solutions and by high-temperature electrodeposition from melts of silver nitrate and chloride. According to the scanning, electron microscopy data, the surface of crystals obtained from solutions contained globular conglomerates, and crystals having the shape of branched dendrites were formed from melts. The subsurface silver layers were studied by X-ray photoelectron spectroscopy and found to contain carbon and oxygen as impurities. The suggestion was made that the high content of oxygen in the subsurface region of silver samples obtained from melts accelerated the transformation of ethylene glycol to glyoxal.