One-step conversion of xylose to furfuryl alcohol on sulfated zirconia-supported Pt catalyst—Balance between acid and metal sites

ZrO2/SO42−/Cu as a Multifunctional, Durable, Efficient, and Heterogeneous Recoverable Inorgano‐Nanocatalyst for the Green Preparation of Quinolines

“…As shown in Scheme , none of used catalysts shows a significant yield in the reaction conditions. Note to the presence of two catalytic active sites in ZrO 2 /SO 4 2− /Cu, so a synergetic effect could be imagined for this catalyst arising from Cu sites, Zr sites, sulfate groups, and coordinated water . A plausible structure for the catalyst was sketched in Scheme , that was in agreement with the characterization data as well as proposed structures in the literature …”

“…XRD pattern of ZrO 2 /SO 4 2− and ZrO 2 /SO 4 2− /Cu are shown in Figure B. ZrO 2 /SO 4 2− XRD pattern demonstrated three characteristic peaks with strong intensities at 2θ= 30.4°, 50.3° and 60.2°, which represent the tetragonal structure of the ZrO 2 /SO 4 2− with high crystallinity (JCPDS 17–0923) (Figure B‐a) . More precisely, a mixture of monoclinic and tetragonal phases could be seen in the spectrum (Figure B‐a, stars and diamonds represent tetragonal and monoclinic structures, respectively), that is in agreement with the reported ZrO 2 /SO 4 2 crystal structure …”

“…To measure the surface acidity of the catalyst, ZrO 2 /SO 4 2− /Cu nanocatalyst was treated by various concentrations of pyridine as a probe molecule. This technique is based on the adsorption of pyridine on the surface of the solid acid catalyst and screened by the corresponding FTIR spectroscopy peaks intensity . This test not only calculates the surface acidity of the catalyst, but also makes it possible to identify and distinguish Lewis‐ and Brønsted acid sites on the catalyst .…”

“…This technique is based on the adsorption of pyridine on the surface of the solid acid catalyst and screened by the corresponding FTIR spectroscopy peaks intensity . This test not only calculates the surface acidity of the catalyst, but also makes it possible to identify and distinguish Lewis‐ and Brønsted acid sites on the catalyst . Figure S1 (†ESI) shows the FTIR spectra of the ZrO 2 /SO 4 2− /Cu and its treatment with various concentrations of pyridine.…”

The CuFe2O4@SiO2@ZrO2/SO42−/Cu nanoparticles: an efficient magnetically recyclable multifunctional Lewis/Brønsted acid nanocatalyst for the ligand- and Pd-free Sonogashira cross-coupling reaction in water

“…Sulfated zirconium oxide was prepared according to a previously reported protocol with slight modication. 21,22 At rst, ZrCl 4 (2.3 g, 10 mmol) as a precursor was dissolved in 10 mL deionized water. The ammonia solution (10 mL, 1 N) was added dropwise for 30 min until the pH was adjusted to 11.…”