Water-dispersible Hollow Microporous Organic Network Spheres as Substrate for Electroless Deposition of Ultrafine Pd Nanoparticles with High Catalytic Activity and Recyclability

Chem Asian J. 2016 Nov 22;11(22):3178-3182. doi: 10.1002/asia.201601225. Epub 2016 Oct 14.

Abstract

Microporous organic networks (MONs) have been considered as an ideal substrate to stabilize active metal nanoparticles. However, the development of highly water-dispersible hollow MONs nanostructures which can serve as both the reducing agent and stabilizer is highly desirable but still challenging. Here we report a template-assisted method to synthesize hollow microporous organic network (H-MON) spheres using silica spheres as hard template and 1,3,5-triethynylbenzene as the building blocks through a Glaser coupling reaction. The obtained water-dispersible H-MON spheres bearing sp- and sp2 -hybridized carbon atoms possess a highly conjugated electronic structure and show low reduction potential; thus, they can serve as a reducing agent and stabilizer for electroless deposition of highly dispersed Pd clusters to form a Pd/H-MON spherical hollow nanocomposite. Benefitting from their high porosity, large surface area, and excellent solution dispersibility, the as-prepared Pd/H-MON hollow nanocomposite exhibits a high catalytic performance and recyclability toward the reduction of 4-nitrophenol.

Keywords: Pd nanoparticles; conjugated electronic structure; electroless deposition; hollow microporous organic networks; water dispersibility.