Enriching Local Reaction Fields via Ordered Multidimensional Interfaces for High-Yield Urea Electrosynthesis

Electrochemical urea (CO(NH₂)₂) synthesis using CO₂ and available nitrogen sources is an alternative method featuring reactant sustainability and an overall energy efficiency. However, sluggish catalytic reaction kinetics for available electrocatalysts led to poor yield rates of urea production, seriously hindering its practical applications, because of the low density of reactant species and electric fields surrounding active sites. Herein, a new class of ordered multidimensional interfaces for electrocatalysts is discovered to enrich the local reaction fields surrounding active sites, thereby facilitating reaction kinetics for urea synthesis with ultrahigh yield rates. Using Cu-based electrocatalysts as a proof of concept, one-dimensional (1D) Cu₂O nanowires were uniformly aligned along the 3-fold symmetry of two-dimensional (2D) Cu₂Se (111) facets through in situ electrochemical epitaxial growth. This unique structure allows for accumulation of gas flows, electric fields, and species concentrations due to the interface confinement effect from multidimensions. Our Cu₂O/Cu₂Se interfaces yield a high current density, with a Faraday efficiency (FE) of 61.5% and a production rate of 0.96 mg h⁻¹ in half cells, representing the highest reported values. Moreover, the designed membrane electrode assembly (MEA) coelectrolysis device demonstrates effective urea synthesis and plastic upcycling for practical applications. Enriching local reaction fields via ordered multidimensional interfaces can enable new strategies for designing efficient electrocatalysts and promoting reaction kinetics for practical applications.