Isolating Cu-Zn active-sites in Ordered Intermetallics to Enhance Nitrite-to-Ammonia Electroreduction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39580449.
- Also identified by DOI 10.1038/s41467-024-53897-9 and PMC identifier 11585598.
- Licence recorded as CC BY-NC-ND.
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Abstract
Electrocatalytic nitrite reduction to the valuable ammonia is a green and sustainable alternative to the conventional Haber-Bosch method for ammonia synthesis, while the activity and selectivity for ammonia production remains poor at low nitrite concentrations. Herein, we report a nanoporous intermetallic single-atom alloy CuZn (np/ISAA-CuZn) catalyst with completely isolated Cu-Zn active-sites, which achieves neutral nitrite reduction reaction with a remarkable NH<sub>3</sub> Faradaic efficiency over 95% and the highest energy efficiency of ≈ 59.1% in wide potential range from -0.2 to -0.8 V vs. RHE. The np/ISAA-CuZn electrocatalyst was able to operate stably at 500 mA cm<sup>-2</sup> for 220 h under membrane electrode assembly conditions with a stabilized NH<sub>3</sub> Faraday efficiency of ~80% and high NO<sub>2</sub><sup>‒</sup> removal rate of ~100%. A series of in situ experimental studies combined with density functional theory calculations reveal that strong electronic interactions of isolated Cu-Zn active-sites altered the protonation adsorption species, effectively alleviating the protonation barrier of *NO<sub>2</sub> and thus greatly facilitating the selective reduction of NO<sub>2</sub><sup>-</sup> into NH<sub>3</sub>.