Tuning the Products of CO₂Electroreduction on a Ni₃Ga Catalyst Using Carbon Solid Supports

Abstract

Certain alloys of nickel have recently been shown to reduce CO2 to multi-carbon products electrochemically without the need for copper. Here we show that Ni3Ga thin film electrocatalysts on carbon electrodes discriminate between CO2 reduction pathways and products based on their surface morphologies, which are controlled by catalyst-carbon support interactions. It is also observed that unsupported, bulk Ni3Ga reduces CO but not CO2. With this understanding, a tandem electrocatalyst utilizing two variants of the Ni3Ga material—one supported and one unsupported—was developed. In this two-electrode system, CO is generated from CO2 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 Ni3Ga during the synthesis of the catalyst, thereby influencing the electrolysis product distribution.