PNNL

Abstract

Utilizing a combination of electron stimulated desorption, infrared spectroscopy and temperature program desorption measurements, we show that molecular water is synthesized during electron irradiation on boehmite nanoplates and postulate that the reaction proceeds first through decomposition of the hydroxyl to produce trapped hydrogen atoms. Once released, these hydrogen atoms can react with a neighboring hydroxyl resulting in adsorbed water. In addition, molecular water is readily formed on the surface of the boehmite nanosheets through thermal induced recombinative desorption. Peak water production via recombinative desorption occurs at 750 K in agreement with previous studies. We have also identified a weak desorption feature near 400 K which is likely strongly adsorbed water. The derived experimental desorption activation energy of water assuming full coverage is 98.6 kJ mol-1.