Consumer Value-Based Electrochemical CO2 Conversion to Ethanol by Employing Eco-Friendly Catalyst Design

Abstract

The electrochemical reduction of CO2 (CO2RR) provides a promising approach to mitigate greenhouse gas emissions while generating value-added chemicals. Among potential products, C-2 species such as ethanol and ethylene are particularly attractive, yet achieving their selective and stable formation remains a major challenge. In this study, we compare two Cu-carbon catalyst synthesis strategies, i.e., chemical exfoliation-reduction (CER) based on a high-temperature acid treatment and hydrothermal (HT) synthesis based on a mild bottom-up method. Structural and electrochemical analyses revealed that HT produces atomically dispersed Cu-N active sites with enhanced selectivity toward ethanol and ethylene (ethanol Faraday efficiency similar to 38% at - 0.4 V, with HER suppressed below 30%), whereas CER yields heterogeneous CuOx clusters that mainly generate C-1 products with high H-2 output. The C2 Faradaic efficiency remained above 30% within the potential range of -0.5 to 0.9 V in 1.0 M KOH electrolyte condition. Beyond catalytic activity, an integrated techno-economic, life-cycle, and social life-cycle (3E) assessment demonstrated that HT offered lower synthesis cost, reduced environmental impact, and greater user acceptance. Collectively, these results establish HT as a more efficient and sustainable pathway for CO2RR catalyst development and highlight the value of coupling electrochemical evaluation with holistic 3E analysis to guide technologies that align performance, sustainability, and social acceptance.