Thermal desorption processes of H2 and CH4 from Li2ZrO3 and Li4SiO4 materials absorbed H2O and CO2 in air at room temperature

Abstract

The thermal desorption processes of hydrogen (H2) and methane (CH4) from lithium-based materials, Li2ZrO3 and Li4SiO4, exposed to air at room temperature of 293 K with a relative humidity of 80%, were investigated using gas chromatography (GC). The GC analysis revealed that the absolute values of the released H2 and CH4 gases at 523 K were approximately 7.42 × 10−6 and 1.54 × 10−6 ml/g for Li2ZrO3, and 3.24 × 10−6 and 0 ml/g for Li4SiO4. The amounts of H2 and CH4 released increased with increase in annealing temperatures and considerably depended on absorption properties of water (H2O) and carbon dioxide (CO2) present in air at room temperature. The production of CH4 at low temperature is due to the intermediate species including CHx precursors produced by the reaction between H split from H2O and Li2CO3 resulting in the CO2 absorption of Li2ZrO3 and Li4SiO4 materials.