Single-atom electrosynthesis of glycine from glyphosate wastewater.

Abstract

The extensive application of glyphosate (PMG) has led to the accumulation of contaminated effluent, posing environmental risks and losing valuable chemical resources. Although electrochemical conversion represents a promising pathway for waste valorization, selectively transforming PMG into a specific high-value product remains challenging. Here, we introduce an integrated electrochemical system to efficiently convert waste PMG to value-added glycine through collaborative redesign of anode and cathode reactions. Isolated iron atoms anchored on copper nanowires (Fe1Cu NWs) to form the efficient cathode catalyst with unique active centers, guiding the selective electrochemical PMG oxidation reaction (PMGOR) to yield glycine with a selectivity of 78.3%, significantly higher than non-selective pure copper nanowires. Such exceptional performance stemmed from the Fe1Cu active centers, promoting PMG adsorption and preventing glycine from over-oxidation via competitive phosphate binding. Meanwhile, anodic oxygen evolution reaction is replaced with ethylene glycol oxidation, significantly lowering the overall energy consumption. This strategy results in a glycine yield rate of 975.6 µmol L-1 h-1 and enables the isolation of high-purity glycinate. Life-cycle and techno-economic analyses demonstrate the substantial sustainability and feasibility of Fe1Cu NWs. This work presents a sustainable electrochemical paradigm for pollution mitigation that converts contaminants into value-added resources with low energy expenditure.