Coupling urea production and energy output in Zn-nitrate/carbon dioxide batteries enabled by porous copper‑nickel bimetallic catalysts.

Conventional urea industry faces dual challenges of high energy consumption and carbon emissions. Although electrochemical co-reduction of nitrates and carbon dioxide (CO₂) offers a promising route for green urea synthesis, its electrical-to-chemical energy conversion efficiency remains constrained by sluggish reaction kinetics and high electrical energy demand. Here, we design and report a nitrogen-doped porous carbon (NC) material embedded with dispersed copper‑nickel bimetal nanoparticles (CuNi/NC) for constructing the first example of a Zn-nitrate/CO2 battery that can output electricity while generating urea with a superior energy efficiency of 1.51 molurea kWh-1 and a urea production rate of 110 mg h-1 gcat-1. The proposed assembled battery exhibits exceptional stability over 300 h, retaining high urea Faradaic efficiency at 36% and yield at 100.9 mg h-1 gcat-1. In situ X-ray absorption spectroscopy, infrared spectroscopy, and density functional theory simulations confirm that the active metal sites facilitate substrate adsorption and stabilize critical intermediates (*N-C-N, *NH₂, and *NO), thereby effectively accelerating CN coupling. This work breaks the 'high-energy, single-function' bottleneck of traditional electrochemical systems, establishing an innovative 'carbon-negative energy supply' paradigm for carbon-neutral agriculture and decentralized energy systems.