Large-Scale Synthesis (75 g/Batch) of Single-Atom Catalysts for Selective Electrochemical CO ₂ Reduction to CO and Commercialization Potential Analysis

A promising approach to mitigate climate change is to use renewable electricity to convert carbon dioxide (CO2) emissions into useful products like carbon monoxide (CO) and hydrocarbons. While research has largely focused on developing high-performance catalysts for electrochemical CO2 reduction (eCO2R), scalability of catalyst synthesis remains underexplored. Metal–nitrogen–carbon (M–N–C) catalysts with dominant single-atom sites are among the most effective materials for CO production, but conventional synthesis methods rely on energy-intensive steps and complex pre- and post-treatment processes, hindering scalability and adding negative environmental impacts. This work demonstrates a scalable, single-step synthesis of M–N–C (M = Ni/Fe) catalysts using commercially available multiwalled carbon nanotubes (MWCNTs) and melamine as the feedstock. The method leverages inherent Ni/Fe impurities in MWCNTs, requiring only moderate-temperature pyrolysis (650 °C) without any pre- or post-treatments. Batch sizes up to 75 g were successfully produced using both regular-grade (>95% carbon content) and cheaper but more impure industrial-grade (>90% carbon content) MWCNTs. Structural, chemical, and electrochemical analyses confirmed reproducibility. Catalysts consistently achieved >98% CO selectivity at commercially relevant current densities (500 mA cm–2), outperforming benchmark Ag nanoparticle catalysts. Techno-economic analysis (TEA) further underscored the commercialization potential, yielding a base case minimum selling price (MSP) of $145 per tonne of CO, $255 below the current CO market price and lower than that obtained using Ag catalysts. Life cycle assessment (LCA) showed significant environmental benefits, registering 21% lower CO2-equivalent emissions compared to using Ag catalysts. Overall, this scalable approach produces high-performance M–N–C catalysts while delivering clear environmental and economic advantages, advancing the commercialization of eCO2R technology.