From bulk metals to single-atoms: design of efficient catalysts for the electroreduction of CO 2 .

The electroreduction of CO 2 (CO 2 RR) is a sustainable approach to mitigate the increased global CO 2 emissions and further produce valuable chemicals. Electrocatalysts are crucial to lower the energy barrier, tune the intricate reaction pathways and suppress the competitive side-reactions. In this feature article, we give a brief overview of our journey in the design of efficient catalysts for the CO 2 RR. From bulk metals to nanoparticles to single-atom catalysts (SACs), we summarize our progress in the design of efficient metal nanoparticles by porosity engineering, defect engineering and alloy engineering, and developing single-atom catalysts with advanced metal sites, coordination environments, substrates and synthesis routes. We highlight the importance of reaction environments and provide an ionic liquid nanoconfinement strategy for local environment modification. In the end, we provide our views and perspectives for the future direction of the CO 2 RR towards commercialization.