Effect of secondary phases on the selectivity of CO2 reduction properties of Mg-based alloy

It is a great challenge to achieve adsorption and desorption of H2 on magnesium-based metal materials under room temperature and ambient pressure. To address this problem, we proposed a strategy to tailing the secondary phases in Mg alloy to directly drive catalytic reactions, and utilizing ambient sunlight-driven solar energy to convert heat energy to promote the adsorption and reaction of H2 and CO2 gas. Thus, the magnesium-based materials can convert CO2 into CO and CH4 under sunlight. Here we report a magnesium-based material LiAl-SiO4/Mg, where MgO/Mg interface and Li4SiO4 particles play different roles in production CO or CH4 under varied solar energy. The large amount of MgO reduced the adsorption of H2 on Mg, while the existence of Li4SiO4 enhanced the production rate of CO. This work explores the functional applications of main-group alloys and paves the way towards ambient sunlight-driven adsorption and use of hydrogen.

Automated summary

This study proposes a strategy to achieve hydrogen adsorption and utilization using magnesium-based alloys under sunlight. By tailoring the secondary phases in the material, catalytic reactions can be directly promoted, leading to the conversion of CO2. The results show that the MgO/Mg interface and Li4SiO4 particles play different roles in various reactions.