Structured Assemblages of Single-Walled 3d Transition Metal Silicate Nanotubes as Precursors for Composition-Tailorable Catalysts

Abstract

Copper silicate has so far been the only transition metal silicate that can be synthesized into a single-walled nanotubular structure. In addition to making single-walled copper silicate nanotubes (CuSiNT) as hollow spherical or bundle-like assemblages, herein, we developed a general method to synthesize a series of new single-walled silicate nanotubes containing other 3d transition metal elements (M = Mn, Fe, Co, Ni, and Zn). After the controllable synthesis of CuSiNT, up to 80% of Cu in the CuSiNT can be replaced with dopant metals (M) through complex-assisted ion exchange, while the original tubular structure remains intact. These metal silicate nanotubes can serve as solid precursors for design-made nanocatalysts; enhanced catalytic performance has been demonstrated using CO2 hydrogenation as a model reaction.