Exploring tribochemical transduction pathways for dehydrogenation of molecular hydrides

Abstract

Recent research has shown that mechanical energy can trigger dehydrogenation (hydrogen release) from metal and complex hydrides at room temperature, offering an alternative to traditional heat-based methods. This study investigates whether the tribochemical approach can also be effective to release hydrogen from molecular hydrides such as ethane 1,2-diamineborane (EDAB). Surprisingly, despite dehydrogenating at a lower temperature than metal and complex hydrides, EDAB exhibited faint hydrogen release under mechanical stress. To understand this behavior, the tribochemical decomposition pathways of EDAB were investigated using operando Mechanically Stimulated Gas Emission Mass Spectrometry in combination with other surface and material characterization techniques. The lack of hydrogen emission from EDAB is attributed to a combination of strong intramolecular bonds (covalent and dative bonds) within the molecule, and weak intermolecular interactions (hydrogen bonds and van der Waals forces) between EDAB molecules.