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, C₂ 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 ~ 38% at − 0.4 V, with HER suppressed below 30%), whereas CER yields heterogeneous CuO_x clusters that mainly generate C₁ products with high H₂ 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.

Graphical abstract