Abstract
Electrolyzing CO(2) into ethylene (C(2)H(4)) is a promising strategy for CO(2) utilization and carbon neutrality since C(2)H(4) is an important industrial feedstock. However, selectively converting CO(2) into C(2)H(4) via the CO(2) electro-reduction reaction (CO(2) ERR) is still a great challenge. Herein, Cu-Cu(2)O nanoparticles anchored on reduced graphene oxide nanosheets (Cu-Cu(2)O/rGO) were prepared from copper hydroxide nanostrands (CHNs) and graphene oxide (GO) nanosheets via in situ electrochemical reduction. Cu-Cu(2)O nanoparticles with diameter less than 10 nm were formed on the surface of rGO nanosheets. After assembling the Cu-Cu(2)O/rGO catalyst into a flow cell, it demonstrated high Faraday efficiencies (FEs) of 55.4%, 37.6%, and 6.7% for C(2)H(4), C(2)H(6), and H(2), respectively, and a total 93% FE for C(2) at -1.3 V vs. the standard hydrogen electrode (SHE). Moreover, its FE was 68.2% for C(2)H(4), 10.2% for C(2)H(6), and 20.5% for H(2) at -1.4 (vs. SHE). Besides, no liquid carbon product was detected. This high selectivity is attributed to the synergistic effect arising from the small diameter of Cu-Cu(2)O NPs with the combination of Cu(0)-Cu(+) and rGO nanosheets, which promotes the activation of CO(2) molecules, facilitates C-C coupling, and enhances stability. This may provide a facile way for designing an efficient catalyst for selectively electrolyzing CO(2) into valuable C(2) chemicals.