The Synthesis of High Purity Sn‐Based Heteronuclear Dual‐Atomic Sites by Pre‐Confined Low‐Temperature Fixing Strategy for Electrocatalytic CO ₂ Reduction

Abstract Carbon‐supported heteronuclear dual‐atom catalysts (DACs) are usually synthesized by high‐temperature pyrolysis. But forming high‐purity heteronuclear dual‐atom sites remains a challenge, due to the co‐existence of other atomic species caused by a random distribution of metal species in the precursor and thermal migration during pyrolysis. Herein, a pre‐confined low‐temperature fixing strategy is developed to anchor heteronuclear dual‐atom pairs on nitrogen‐doped carbon (NC). As a proof of concept, organotin‐based bimetallic complexes (M/Sn‐L) with low carbonization temperature are synthesized based on a Stille‐coupling reaction. The M/Sn‐L can be transformed into DACs with high purity of heteronuclear dual‐atom pairs (≈90%) at low‐temperature pyrolysis (400 °C), which effectively mitigates thermal migration. Among these DACs, Ni/Sn DACs is active for the electroreduction of CO 2 to CO. The faradaic efficiency and turnover frequency is 98.1% and 35734 h −1 , respectively. Density functional theory reveals the regulation of the electronic structure of the Sn active sites induced by the electron transfer between Ni and Sn, leading to a reduced energy barrier for CO 2 hydrogenation, the rate‐determined step in CO 2 ‐to‐CO conversion. This work highlights the importance of utilizing low carbonization temperature precursor in synthesizing carbon‐supported heteronuclear DACs, which provides a suitable platform to study the intrinsic catalytic properties of DACs.