Key points are not available for this paper at this time.
Abstract The electrochemical conversion of carbon dioxide (CO 2 ) to methane (CH 4 ), which can be used not only as fuel but also as a hydrogen carrier, has drawn great attention for use in supporting carbon capture and utilization. The design of active and selective electrocatalysts with exceptional CO 2 ‐to‐CH 4 conversion efficiency is highly desirable; however, it remains a challenge. Here a molecular tuning strategy−in situ amine functionalization of nitrogen‐doped graphene quantum dots (GQDs) for highly efficient CO 2 ‐to‐CH 4 conversion is presented. Amine functionalized nitrogen‐doped GQDs achieve a CH 4 Faradic efficiency (FE) of 63% and 46%, respectively, at CH 4 partial current densities of 170 and 258 mA cm −2 , approximating to or even outperforming state‐of‐the‐art Cu‐based electrocatalysts. These GQDs also convert CO 2 to C 2 products mainly including C 2 H 4 and C 2 H 5 OH with a maximum FE of ≈10%. A systematic analysis reveals that the CH 4 yield varies linearly with amine group content, whereas the C 2 production rate is positively dependent on pyridinic N dopant content. This work provides insight into the rational design of carbon catalysts with CO 2 ‐to‐CH 4 conversion efficiency at the industrially relevant level.
Yadav et al. (2021) studied this question.