Size-effect induced controllable Cu(0)-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.