Catalytic formic acid dehydrogenation via hexagonal-boron nitride supported palladium

Formic acid dehydrogenation is an effective pathway for hydrogen storage, transportation, and in situ supply; however, the problems of catalyst sintering and agglomeration remain challenging. In this regard, this study aims at modulating hexagonal boron nitride-supported Pd catalyst with strong metal support interactions, thereby promoting its long-term stability. Effects of particle sizes of h-BN (500 nm, 1-2 mm, 5-10 mm) and dehydrogenation temperatures on formic acid conversion, hydrogen yield, CO concentra-tion, and product distribution are investigated. The nano-scaled h-BN supported Pd nanoparticles show the best performance of 24.25 mmol H2 mL-1 HCOOH with a H2 con-centration of 44.7 vol%. Characterizations such as N2 adsorption and desorption, XRD, TEM-EDX mapping, and XPS are used to study the physicochemical properties of the as- synthesized and reacted catalysts. Specifically, the diffraction peaks of Pd cannot be detected from XRD, possibly attributing to the homogeneous dispersion of its nano particles, as confirmed by the TEM-EDX mapping results. The durability tests indicate that the Pd/h-BN (500 nm) catalyst remains long-term stability under a temperature as high as 160 degrees C. Moreover, results from XPS reveal that there is a strong interaction between the Pd nanoparticles and the hexagonal BN support, as proved by the electronic transformation from Pd to N by XPS, thereby enhancing the stability of the Pd/h-BN catalyst.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.