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Urea synthesis through the simultaneous electrocatalytic reduction of N₂and CO₂molecules under ambient conditions holds great promises as a sustainable alternative to its industrial production, in which the development of stable, highly efficient, and highly selective catalysts to boost the chemisorption, activation, and coupling of inert N₂and CO₂molecules remains rather challenging. Herein, by means of density functional theory computations, we proposed a new class of two‐dimensional nanomaterials, namely, transition‐metal phosphide monolayers (TM₂P, TM = Ti, Fe, Zr, Mo, and W), as the potential electrocatalysts for urea production. Our results showed that these TM₂P materials exhibit outstanding stability and excellent metallic properties. Interestingly, the Mo₂P monolayer was screened out as the best catalyst for urea synthesis due to its small kinetic energy barrier (0.35 eV) for C–N coupling, low limiting potential (−0.39 V), and significant suppressing effects on the competing side reactions. The outstanding catalytic activity of the Mo₂P monolayer can be ascribed to its optimal adsorption strength with the key *NCON species due to its moderate positive charges on the Mo active sites. Our findings not only propose a novel catalyst with high‐efficiency and high‐selectivity for urea production but also further widen the potential applications of metal phosphides in electrocatalysis. 

Abstract. Copper/zinc superoxide dismutase (CuZnSOD), a 32.5 kDa metalloprotein with a radius of ca. 2.1 nm, catalyses the superoxide to hydrogen peroxide and molecular oxygen. At the femtomolar concentration range, has been sensed through electrochemical catalytic amplification using a Pt ultramicroelectrode. During amperometric (i vs. t) analysis, cathodic and anodic current transitions peaks were seen, in agreement with the metalloprotein catalytic mechanism. The current amplitudes were analyzed and correspond to the CuZnSOD dimensions. Thermal treatment of metalloprotein samples at 80 °C showed larger current spikes suggesting aggregation without losing its catalytic capability. The size was confirmed by transmission electron microscopy. Resumen. Cuprozinc superóxido dismutasa (CuZnSOD), es una metaloproteina de 32.5 kDa con un radio de aproximadamente 2.1 nm. Esta enzima cataliza la reacción de superóxido a peróxido y oxígeno molecular. Por primera vez, esta proteína es detectada a concentraciones femtomolares haciendo uso de la técnica electroquímica conocida como amplificación catalítica y la tecnología de ultra-microelectrodos de Pt. Durante un análisis amperométrico (curvas i vs. t), se observaron picos transitorios de corriente catódica y anódica que concuerdan con el mecanismo catalítico de la enzima. Al analizar la amplitud de la corriente, la misma concuerda con las dimensiones de CuZnSOD. Luego de exponer la proteína a un tratamiento térmico de 80 °C, CuZnSOD mostró picos de corriente transitorias que sugieren aglomeración de la enzima sin perder su capacidad catalítica. El tamaño fue confirmado por microscopía electrónica de transmisión.