Lattice-strained Pd nanoclusters embedded into NiMoO4 nanorods: Manipulating active hydrogen to intensify nitrite hydrogenation for ammonia production and electricity supply

Electrocatalytic nitrite (NO 2 - ) reduction reaction (NO 2 RR) represents a promising low-carbon strategy for sustainable ammonia (NH 3 ) synthesis, wherein the management of active hydrogen (*H) species plays a pivotal role. Precise regulation of *H supply and fundamental understanding of its dynamics are critical for optimizing NH 3 synthesis efficiency. Herein, the lattice-strained Pd nanoclusters integrated NiMoO 4 nanorods were introduced to design an advanced electrocatalytic system for efficiently triggering NO 2 RR. The resulting Pd-NiMoO 4 heterostructures demonstrate exceptional NO 2 RR performance, achieving a Faradaic efficiency (FE) of 92.22 % and an ultralow energy consumption of 15.5 kWh kg −1 for NH 4 + production at 0 V vs RHE. In situ characterizations and theoretical calculations reveal that the Pd-NiMoO 4 heterostructure facilitates efficient *H generation and maintains high surface *H-coverage due to the heterointerface-induced charge redistribution effect. Building upon this catalytic design, we further developed a Zn-nitrite battery and a novel borohydride (BH 4 - )-nitrite fuel cell employing Pd-NiMoO 4 /NF as the active electrode. These devices achieve a considerable open-circuit voltage, enabling simultaneous electricity generation and NH 4 + production. This work not only introduces a high-performance electrocatalyst for low-potential NH 3 synthesis but also establishes a versatile platform for multifunctional energy conversion systems. • Lattice-strained Pd nanoclusters embedded into NiMoO 4 nanorods were fabricated. • Charge-reconfigured surface enhances *NO 2 -adsorption and *H-coverage. • Pd-NiMoO 4 /NF manifests exceptional performance for ultralow potential NH 3 synthesis. • Novel borohydride-nitrite fuel cell based on Pd-NiMoO 4 /NF is proposed.