Size-effect induced controllable Cu0-Cu+ sites for ampere-level nitrate electroreduction coupled with biomass upgrading

The synergistic Cu 0 -Cu + sites is regarded as the active species towards NH 3 synthesis from the nitrate electrochemical reduction reaction (NO 3 - RR) process. However, the mechanistic understanding and the roles of Cu 0 and Cu + remain exclusive. The big obstacle is that it is challenging to effectively regulate the interfacial motifs of Cu 0 -Cu + sites. In this paper, we describe the tunable construction of Cu 0 -Cu + interfacial structure by modulating the size-effect of Cu 2 O nanocube electrocatalysts to NO 3 - RR performance. We elucidate the formation mechanism of Cu 0 -Cu + motifs by correlating the macroscopic particle size with the microscopic coordinated structure properties, and identify the synergistic effect of Cu 0 -Cu + motifs on NO 3 - RR. Based on the rational design of Cu 0 -Cu + interfacial electrocatalyst, we develop an efficient paired-electrolysis system to simultaneously achieve the efficient production of NH 3 and 2,5-furandicarboxylic acid at an industrially relevant current densities (2 A cm −2 ), while maintaining high Faradaic efficiencies, high yield rates, and long-term operational stability in a 100 cm 2 electrolyzers, indicating promising practical applications.