Efficient and stable CO2 to formate conversion enabled by edge-site-enriched SnS2 nanoplates

Layered materials have been investigated in many different catalytic reactions due to their excellent functionalities. In particular, understanding the anisotropic properties of layered materials is important for the design of more efficient catalysts. Herein, SnS₂ nanoflakes with abundant edge sites (E-SnS₂) were synthesized and their catalytic properties towards the electrochemical CO₂ reduction reaction (CO₂RR) were studied. Combining experimental data and computational analysis, we found that the edge sites of SnS₂ are more active for CO₂ to formate conversion compared with the basal sites. Moreover, a CO₂ reduction intermediates triggered activation mechanism at the edge sites is proposed, the formation of sulfur vacancies at the edges would generate more active sites for CO₂RR. The as-synthesized E-SnS₂ shows high selectivity, activity and robust stability for at least 12 h in a flow cell under a current density of − 200 mA·cm^-2. This work may provide a new perspective on rational catalyst design for CO₂RR.