Tuning the Coordination Structure of CuNC Single Atom Catalysts for Simultaneous Electrochemical Reduction of CO<sub>2</sub> and NO<sub>3</sub><sup>–</sup> to Urea
Josh Leverett, Thành Trần‐Phú, Jodie A. Yuwono, Priyank V. Kumar, Changmin Kim, Qingfeng Zhai, Han Chen, Jiangtao Qu, Julie M. Cairney, Alexandr N. Simonov, Rosalie K. Hocking, Liming Dai, Rahman Daiyan, Rose Amal
Abstract
Abstract Closing both the carbon and nitrogen loops is a critical venture to support the establishment of the circular, net‐zero carbon economy. Although single atom catalysts (SACs) have gained interest for the electrochemical reduction reactions of both carbon dioxide (CO 2 RR) and nitrate (NO 3 RR), the structure–activity relationship for Cu SAC coordination for these reactions remains unclear and should be explored such that a fundamental understanding is developed. To this end, the role of the Cu coordination structure is investigated in dictating the activity and selectivity for the CO 2 RR and NO 3 RR. In agreement with the density functional theory calculations, it is revealed that Cu‐N 4 sites exhibit higher intrinsic activity toward the CO 2 RR, whilst both Cu‐N 4 and Cu‐N 4− x ‐C x sites are active toward the NO 3 RR. Leveraging these findings, CO 2 RR and NO 3 RR are coupled for the formation of urea on Cu SACs, revealing the importance of *COOH binding as a critical parameter determining the catalytic activity for urea production. To the best of the authors’ knowledge, this is the first report employing SACs for electrochemical urea synthesis from CO 2 RR and NO 3 RR, which achieves a Faradaic efficiency of 28% for urea production with a current density of − 27 mA cm –2 at − 0.9 V versus the reversible hydrogen electrode.