Theoretical Study of In<sub><i>x</i></sub>Ru<sub><i>y</i></sub> Alloys for Efficient Electrocatalytic\nReduction of Nitrate to Ammonia

The\nelectrochemical reduction of nitrate to ammonia is considered\na feasible strategy to address the imbalance of the global nitrogen\ncycle by eliminating N-containing pollutants in wastewater while producing\nammonia in a sustainable way. In this work, we systematically investigate\nthe reduction of nitrate to ammonia on p-block indium (In), noble\nmetal ruthenium (Ru), and their alloys (InRu<sub>3</sub>, In<sub>3</sub>Ru). We found that pure In and Ru candidates exhibit various performances\nfor nitrate reduction with low limiting potentials for the potential-determining\nstep of −0.31 V and −0.14 V, respectively. However,\nthe incorporation of In into Ru to create alloys leads to excellent\nactivity for the reduction of nitrate to ammonia. Ammonia production\non InRu<sub>3</sub> and In<sub>3</sub>Ru alloys demonstrates higher\ncatalytic activity and selectivity as the byproducts of NO<sub>2</sub> and NO can be inhibited, while the parasitic hydrogen evolution\nreaction (HER) can also be significantly suppressed. Our work not\nonly proposes efficient electrocatalysts for nitrate reduction but\nalso provides a new strategy for the rational design of alloy catalysts\nfor improved catalytic performance.