One-pot prepared mesoporous silica SBA-15-like monoliths with embedded Ni particles as selective and stable catalysts for methane dry reforming

Abstract

Ni@SBA-15 monoliths with up to 5 wt.% of Ni were successfully synthetized by means of an original and easy one-pot sol-gel method. Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Temperature-Programmed Reduction (TPR), Pair Distribution Function (PDF) and X-Ray Diffraction (XRD) were used for the structural characterization of the samples. After H2-reduction, those solids exhibited small Ni° particles (between 1–3 nm) highly dispersed (one of the highest dispersion reported in the literature to date for 5 wt.% Ni/Silica materials) in strong interaction with the silica support. Scanning Transmission Electron Microscopy in the High Angle Annular Dark Field (STEM/HAADF) mode, chemical mapping by Energy Dispersive X-Ray (EDX) spectroscopy and electron tomography in STEM-HAADF mode highlighted the presence of Ni particles homogeneously distributed, especially in the mesopores. Such confined Ni nanoparticles were shown to be very selective and stable in the dry reforming of methane.