Ammonia Formation Pathway

Nat. Commun.: Moderate metal-support interactions, DFT explanation of efficient Ru-Co(OH)₂ nitrate ammonia production

Nitrate electroreduction for ammonia production converts NO₃⁻ in wastewater into NH₃, simultaneously achieving pollutant treatment and resource recovery. However, most catalysts require negative potential operation, resulting in high energy consumption and limited energy efficiency. This Nature Communications paper describes three types of catalysts constructed by loading Ru clusters onto different metal hydroxide supports using a self-corrosion strategy: Ru-Co(OH)₂, Ru-Ni(OH)₂, and Ru-Fe(OH)₂. The results show that Ru-Co(OH)₂ exhibits moderate metal-support interactions, simultaneously optimizing NO₃⁻ adsorption and interfacial water splitting, achieving highly efficient NO₃⁻ reduction for ammonia production at positive potential. Theoretical calculations further illustrate that the advantage of Ru-Co(OH)₂ comes from the “moderate interaction”: the Ru site provides suitable NO₃⁻ adsorption, and Co(OH)₂ promotes H₂O dissociation and *H supply, thereby accelerating the continuous hydrogenation process from NO₃⁻ to NH₃.