Microenvironment Engineering to Promote Selective Ammonia Electrosynthesis from Nitrate over a PdCu Hollow Catalyst

Abstract

The electrosynthesis of recyclable ammonia (NH3) from nitrate under ambient conditions is of great importance but still full of challenges for practical application. Herein, an efficient catalyst design strategy is developed that can engineer the surface microenvironment of a PdCu hollow (PdCu‐H) catalyst to confine the intermediates and thus promote selective NH3 electrosynthesis from nitrate. The hollow nanoparticles are synthesized by in situ reduction and nucleation of PdCu nanocrystals along a self‐assembled micelle of a well‐designed surfactant. The PdCu‐H catalyst shows a structure‐dependent selectivity toward the NH3 product during the nitrate reduction reaction (NO3−RR) electrocatalysis, enabling a high NH3 Faradaic efficiency of 87.3% and a remarkable NH3 yield rate of 0.551 mmol h−1 mg−1 at ‐0.30 V (vs reversible hydrogen electrode). Moreover, this PdCu‐H catalyst delivers high electrochemical performance in the rechargeable zinc‐NO3− battery. These results provide a promising design strategy to tune catalytic selectivity for efficient electrosynthesis of renewable NH3 and feedstocks.

Structural engineering of catalysts for ammonia electrosynthesis from nitrate: recent advances and challenges

“…Among them, (f) Schematic illustrations for NitRR over PdCu-P with high selectivity. (g) The relationships between FE of NH 3 and rotating rates over PdCu-H, PdCu-P, and Pd-P. 140 Copyright 2023, Wiley.…”

“…À within 3D channels of the SAA catalyst during the NitRR. Moreover, the PdCu hollow (PdCu-H) catalyst was prepared via in situ reduction and nucleation of PdCu nanocrystals along a self-assembled micelle of a well-designed surfactant, 140 which aimed to confine the intermediates and promote selective NH 3 electrosynthesis from nitrate (Fig. 8g).…”

Recent Progress and Perspectives on Transition Metal-Based Electrocatalysts for Efficient Nitrate Reduction

“…This was achieved over a wide pH range, and the optimum FE of the produced NH 3 was close to 100%. Min et al 100 designed a PdCu hollow (PdCu-H) catalyst to promote the electrocatalytic nitrate-selective reduction to NH 3 by improving the surface microenvironment to confine the intermediates. Compared to the nitrate reduction performance of the PdCu nanoparticles (PdCu-P) (Figure 5g), PdCu-H with a hollow structure on the surface was found to be highly selective and active toward NH 3 (Figure 5h).…”

“…Recently, besides the studies on the above-mentioned noble metal alloy catalysts, additional studies have been conducted on double transition metal alloys as well as Cu-based alloy catalysts, such as Cu-Ni, Cu-Co, ,− Cu-Pd, ,− Co-Ni, ,− and Co-Fe. , Results on electrochemical nitrate reduction using other metal alloy catalysts have also been obtained. Zhang et al synthesized a CuNi nanoalloy catalyst (CFP-Cu 1 Ni 1 ) on carbon-fiber paper, which allowed the metal nanoparticles to be well dispersed and the elements to be uniformly mixed.…”

Cu/NiO nanorods for efficiently promoting the electrochemical nitrate reduction to ammonia

“…23 However, the valence state of nitrogen varies, and the reduction process involves the transfer of multiple electrons and protons, which is complex and prone to having side reactions, generating NO 2 , HNO 2 , N 2 O, N 2 , etc . 24–26 Meanwhile, ENO 3 RR has a highly competitive hydrogen evolution reaction (HER), which makes the selectivity of the reaction less satisfactory. 27 Therefore, it is pivotal to decrease the generation of by-products and hydrogen evolution.…”