Pd Single-Atom-Doped Cu₃Co Quantum Dots With Optimized Hydrogenation Kinetics for Versatile Aluminum-Nitrate Primary...

The rational design of nitrate batteries enabling simultaneous electricity generation and pollutant degradation is highly promising, yet most reported systems, such as Zn-nitrate or aldehyde-nitrate batteries, face critical limitations, including sluggish cathodic nitrate reduction kinetics, high anode material cost, low-value anode reaction products, inferior open-circuit potential (OCP), and limited power output. Optimizing catalyst activity and NH₃ selectivity via structure-activity relationships is pivotal to enhancing the electrical output efficiency of such batteries. Herein, we report a Pd single-atom-doped Cu₃Co quantum dots electrocatalyst (Pd_sa-Cu₃Co QDs), which modulates H* adsorption to accelerate the key hydrogenation steps of NO₃RR, achieving a positive onset of +0.18 V (vs. RHE) and nearly 100% Faradaic efficiency (FE) for NH₃ at -0.5 V (vs. RHE). A novel Al-NO₃ ^- primary battery is further constructed by coupling cathodic NO₃RR with anodic aluminum oxidation, enabling cathodic NH₃ production and anodic conversion of waste aluminum (e.g., used Cola cans) to green H₂ and high-value alums. This battery exhibits an OCP of 1.26 V, 8.85 mW cm^-2 peak power density, and an FE of 48.78% NH₃, 56.88% H₂, and yield 56.10% alum, significantly enhancing its economic viability and practical application.