Rapid-heating-assisted metal？support interaction formation: Pd nanoparticles on boron nitride nanotubes as electrocatalysts for high N₂-to-ammonia yields

Abstract

The electrochemical nitrogen (N2) reduction reaction (eNRR) is pivotal for synthesizing green ammonia (NH3) under ambient conditions. However, challenges such as mitigating the detrimental hydrogen evolution reaction (HER) and overcoming the sluggish proton-coupled electron transfer (PCET) step limit the efficiency of the eNRR process. Here, we present a metal？support heterostructure catalyst comprising uniform and high-density palladium nanoparticles (Pd NPs) on defective boron nitride nanotubes (D-BNNTs) via the rapid radiative Joule-heating method. Notably, the strong electronic metal？support interaction (EMSI) between the BNNT defects and Pd NPs creates an electron-deficient state in the Pd NPs, significantly reducing the PCET step and suppressing the HER. This unique configuration of the Pd NPs supported on the D-BNNT catalyst exhibits outstanding NH3 selectivity, achieving 68.0% in neutral aqueous electrolytes and 58.9% in acidic media with a yield rate of 8.69 × 10？10 mol s？1 cm？2. This approach offers a strategic pathway for catalyst engineering in electrochemical reactions, presenting significant potential for practical applications.