Fig. 3: Structural characterization of Co@Si0.95 catalyst.
From: Silica accelerates the selective hydrogenation of CO2 to methanol on cobalt catalysts
a TEM image of Co@Si0.95. b–e, b HAADF-STEM image and EDX elemental maps of c Co, d O, and e Si of Co@Si0.95. f, g HRTEM images of Co@Si0.95. The orange circles highlight the Co nanoparticles (inset of f: size distribution of Co nanoparticles.) h FFT image of the Co nanoparticles corresponding to the HRTEM image in g. Scale bars: 100 nm in a–e, 20 nm in f, and 5 nm in g. i FT-IR spectra of Co@Si0.95 samples. j, k Co K-edge X-ray absorption spectra. j XANES spectra (inset: enlarged pre-edge region) and k EXAFS spectra with k2-weighted data (solid line) and fit corresponding to recommended model (dashed line) of Co@Six and Co/SiO2 samples. l In situ Co 2p XPS spectra of Co3O4@Si0.95 under 0.1 mbar of H2 at various temperatures.
