Synthesis, characterization and catalytic application of Cr–SBA-1 mesoporous molecular sieves

A series of Cr–SBA-1 (Pm3n) mesoporous molecular sieves were directly synthesized under strongly acidic conditions using ammonium dichromate as chromium source and characterized by various techniques. X-ray diffraction (XRD) showed that the synthesized mesoporous materials had a well-ordered cubic structure. N2 adsorption/desorption measurements confirmed that the resultant samples had large mesopores (>23 Å) and highly surface areas (>1000 m2 g−1). FT-IR and UV–vis results revealed that both monochromate and polychromate coexisted on these mesoporous materials. All these samples prepared by direct synthesis have been used as catalysts for dehydrogenation of ethane with carbon dioxide. Among these catalysts, Cr–SBA-1(III) exhibited the highest catalytic performance, giving 21.2% of ethylene yield with a selectivity of 86.9% at 650 °C, whereas, its catalytic activity is lower than that of Cr–SBA-1 prepared by conventional impregnation.

Graphical abstractCr–SBA-1 mesoporous molecular sieves were newly prepared by direct synthesis. The four samples with different Cr content (Fig. 1a–d) show an intense (2 1 0) reflection and smaller (2 0 0) and (2 1 1) reflections in the region of 2θ = 1.5–3°, which are indexed to Pm3n space group. Figure optionsDownload full-size imageDownload as PowerPoint slide