Sn Quantum Dots for Electrocatalytic Reduction of CO₂ to HCOOH

Abstract

Sn based materials, as low-cost and earth-abundant electrocatalysts, are potential candidates for CO2 reduction reaction (CO2RR) into liquid fuels. Unfortunately, the low selectivity and stability limits their applications. Herein, we developed an electrocatalyst of Sn quantum dots (Sn-QDs) for efficient, durable and highly selective CO2 reduction to HCOOH. The Sn-QDs were confirmed with high crystallinity and an average size of only 2-3 nm. The small particle size endowed the electrocatalyst with improved electrochemical active surface area (ECSA), which was about 4.4 times of that of Sn particle. The enlarged ECSA as well as accelerated CO2RR kinetics favored the electrochemical conversion of CO2. The Faradaic efficiency of HCOOH (FEHCOOH) on Sn-QDs/CN reached up to 95% at -1.0 V (vs RHE), which exceeded 83% in the recorded wide potential window of 0.5 V. Moreover, the Sn-QDs electrocatalyst exhibited good electrochemical durability for 24 h.

Recent development of nanomaterials for carbon dioxide electroreduction

“…Over the past decades, QDs have merits of small size, superior monodispersity, and higher surface‐to‐volume ratio, which help design efficient CO 2 RR catalysts. They could be divided into metal‐based QDs, such as Pb/Au/Ag/Cu vacancy‐rich QD‐derived catalysts (QDDCs), 13 Sn QDs, 14 InP colloidal quantum dots (CQDs), 15 and metal‐free‐based QD, such as GQDs or other carbon nanodots 16 . GQD has been shown to exhibit copper‐like activity to reduce CO 2 into high‐order hydrocarbon 17–20 .…”