Interconnected Pd Nanoparticles Supported on Zeolite-AFI for Hydrogen Detection under Ultralow Temperature

• Published in: ACS applied materials & interfaces 2019-10, Vol.11 (40), p.36847-36853
• Main Authors: Du, Lingling, Yuan, Mengqi, Wei, Hongrui, Xing, Xiaxia, Feng, Dongliang, Liao, Yunlong, Chen, Haijun, Yang, Dachi
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.9b12272

The stability for a hydrogen sensor is of crucial importance under a low-temperature range (e.g., 200–400 K), especially in critical environments (e.g., aerospace). However, the “reverse sensing behavior” of Pd-based sensing materials at low temperatures limits their wide application. Herein, a three-dimensional (3D) hydrogen-sensing material of interconnected Pd nanoparticles supported on zeolite-AFI (zeolite-AFI@Pd NPs) is designed for the hydrogen sensor at low temperature. The interconnected Pd NPs of ∼15 nm in diameter are achieved onto the zeolite-AFI framework by reduction-controlled self-assembly growth, followed by partially etching-off zeolite. The 3D structure provides a larger surface ratio for improving hydrogen adsorption onto Pd, and more space for PdHx intermediate expansion, which effectively facilitates response to hydrogen and suppresses the α–β phase transition. Remarkably, there is no “reverse sensing behavior” observed in zeolite-AFI@Pd NPs, though temperature is as low as to 200 K compared with that of pristine Pd nanowires at 287 K. Furthermore, the zeolite-AFI@Pd NPs sensors yield excellent sensing response and high stability to hydrogen at temperature from 200 to 400 K. Such Zeolite-AFI@Pd NPs sensors are expected to detect hydrogen leakage, especially in critical environments of low temperature.