No abstract

Electrochemical nitrogen reduction reaction (NRR) is a burgeoning field for green and sustainable ammonia production, in which numerous potential catalysts emerge in endless. However, satisfactory performances are still not realized under practical applications due to the limited solubility and sluggish diffusion of nitrogen at the interface. Herein, molecularly imprinting technology is adopted to construct an adlayer with abundant nitrogen imprints on the electrocatalyst, which is capable to selectively recognize and proactively aggregate high‐concentrated nitrogen at the interface while hindering the access of overwhelming water simultaneously. With this favourable microenvironment, nitrogen could preferentially occupy the active surface, and the NRR equilibrium could be positively shifted to facilitate the reaction kinetics. Approximately threefold improvements in both ammonia production rate (185.7 µg h−1 mg−1) and Faradaic efficiency (72.9%) are achieved by a metal‐free catalyst compared with the bare one. We believe that the molecularly imprinting strategy should be a general method to find further applicability in numerous catalysts or even other reactions facing similar challenges.This article is protected by copyright. All rights reserved

No abstract

As the core of low‐temperature direct ammonia fuel cell (DAFC) technology, electrocatalytic ammonia oxidation reaction (AOR) has proven to be most active on platinum‐based catalysts. However, the AOR is extremely surface sensitive that only the Pt (200) facet exhibits high reaction activity, whereas other facets usually do not make contributions. Herein, the inert (220) surface of PtMo nano‐alloy is successfully awakened as one more active facet in addition to (200) via directional single‐atom Ni‐doping. The introduction of Ni triggers a targeted electron accumulation around Pt sites at the (220) facet that significantly reduces the AOR energy barrier while maintaining the activity of the (200) surface. With a greatly enlarged active surface, the Ni‐decorated PtMo catalyst exhibits a significantly facilitated AOR kinetics with a low onset potential of 0.49 V versus reversible hydrogen electrode and a superior peak current density of 94.96 A g−1 at 5 mV s−1. Notably, the DAFC equipped with such an electrocatalyst reaches a remarkable peak power density of 16.70 mW cm−2 at low temperatures. It is believed that this strategy sheds light on exploiting the intrinsic activity of Pt‐based electrocatalysts, and drives the low‐temperature DAFC technology to a more practical level.

No abstract