Ionic liquid-modified fibrous silica microspheres loaded with PbS nanoparticles and their enhanced catalytic activity and reusability for the hydrogen production by selective dehydrogenation of formic acid

A new type of catalyst based on the ionic liquid (IL) modified fibrous nano-silica material KCC-1, with a high surface area, as the support and PbS nanoparticles (NPs) as the active sites (KCC-1/IL/PbS), has been successfully prepared through a facile and environmentally-friendly approach and characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The synthesized catalyst exhibited high catalytic performance in the selective dehydrogenation of aqueous solutions of HCOOH/HCOONa to H2 and CO2 gas due to not only the unique dendritic fibrous morphology of the support, which made the active sites accessible, but also the synergistic effect between KCC-1/IL and the small PbS NPs. Additionally, KCC-1/IL/PbS had good recyclability, mainly attributed to the IL groups, which acted as robust anchors to avoid PbS NP leaching from the support. This synthetic method provides a green way to effectively prepare low cost PbS based catalysts and is promising for the development of other useful materials.