Laser-Fabricated Graphene-Supported Copper Nanoparticles for Electrochemical CO 2 Reduction

In this work, a laser-assisted nanomaterial preparation (LANP) method is utilized to fabricate Cu nanoparticles (NPs) supported on graphene. Because LANP is performed at room temperature and under ambient pressure, it enables the production of monodispersed Cu NPs supported on a few-layer graphene carbon network. These small Cu NPs (∼10 nm) exhibit the catalytic ability to reduce CO 2 to HCOOH, CH 3 OH, CO, CH 4, and C 2 H 4 . We study the graphene-supported Cu electrocatalysts as a function of the applied potential and find that CH 4 is generated in high selectivity (85% Faradaic efficiency) at −2.4 V vs RHE. Furthermore, the selectivity of products can be tuned by the addition of a proton-conducting fluoropolymer (Nafion) overlayer of 2 or 15 μm. The Cu NPs in conjunction with Nafion enhance C 2 H 4 production through the dimerization of a Nafion-stabilized Cu-CO intermediate. Taken together, these results demonstrate that the LANP method can be used to construct CO 2 reduction catalysts with a controlled selectivity.