Tuning the products of CO ₂ electroreduction on a Ni ₃ Ga catalyst using carbon solid supports

Certain alloys of nickel have recently been shown to reduce CO ₂ to multi-carbon products electrochemically without the need for copper. Here we show that Ni ₃ Ga thin film electrocatalysts on carbon electrodes discriminate between CO ₂ reduction pathways and products based on their surface morphologies, which are controlled by catalyst-carbon support interactions. It is also observed that unsupported, bulk Ni ₃ Ga reduces CO but not CO ₂ . With this understanding, a tandem electrocatalyst utilizing two variants of the Ni ₃ Ga material—one supported and one unsupported—was developed. In this two-electrode system, CO is generated from CO ₂ on an electrode optimized for this process, and the CO is then further reduced to methanol in the same reactor. It appears that choice of carbon support impacts the morphology of Ni ₃ Ga during the synthesis of the catalyst, thereby influencing the electrolysis product distribution.