Direct epoxidation of propylene to propylene oxide over RuO2-CuO-NaCl-TeO2-MnOx/SiO2 catalysts

Insight into the Effect of Copper Substitution on the Catalytic Performance of LaCoO3-Based Catalysts for Direct Epoxidation of Propylene with Molecular Oxygen

“…Another work which employed Cu/SiO 2 as a composite catalyst came to the similar conclusion (selectivity of 17.0%, conversion of 3.2%) . Although much efforts have been made toward the direct epoxidation of propylene with molecular oxygen, the reaction mechanism and active phase while using Cu-based catalysts still remain vague and contradictory. ,− …”

Direct Propylene Epoxidation over RuO2–CuO–NaCl–TeO2–MnOx/SiO2 Catalysts: Optimized Operating Conditions and Catalyst Characterization

“…The optimal RuO 2 −CuO− NaCl−TeO 2 −MnO x /SiO 2 catalyst previously reported contained metal weight ratios of Ru/Cu/Na/Te/Mn = 7.14/3.57/ 1.79/0.175/1.00 at 25.0 wt % total metal loading on SiO 2 (i.e., representing Ru, Cu, Na, Te, and Mn = 13.06, 6.53, 3.26, 0.32, and 1.83 wt % on SiO 2 , respectively). 38 Typically, the SiO 2supported catalyst (25 mg batch −1 ) was prepared by a coimpregnation method. The SiO 2 support (18.75 mg, amorphous fumed silica, Alfa Aesar) was weighed and contained in a glass shell vial (volume size = 11.1 mL, Fisherbrand).…”

“…This material exhibited high activity for the epoxidation of propylene to PO using only O 2 under atmospheric pressure. 38 In that report, we mainly focused on the optimization of PO formation by varying metal ratios, total metal loading on a SiO 2 support, and the operating conditions (i.e., reactor temperature and O 2 /C 3 H 6 feed gas ratio). We found that the optimal metal weight ratio of Ru/Cu/Na/Te/ Mn at 7.14/3.57/1.79/0.175/1.00 and the total metal loading of 25.0 wt % on a SiO 2 support produced a maximized PO formation rate of 1258 g PO h −1 kg cat −1 .…”

“…Recently, we reported an improvement of the PO formation rate for RuO 2 –CuO–NaCl/SiO 2 catalysts by adding TeO 2 and MnO x . This material exhibited high activity for the epoxidation of propylene to PO using only O 2 under atmospheric pressure . In that report, we mainly focused on the optimization of PO formation by varying metal ratios, total metal loading on a SiO 2 support, and the operating conditions (i.e., reactor temperature and O 2 /C 3 H 6 feed gas ratio).…”

Cerium(IV) Sulfate as a Cocatalyst for Promoting the Direct Epoxidation of Propylene by Ruthenium Porphyrin with Molecular Oxygen

“…The main challenge for direct propylene epoxidation using molecular oxygen is that the allylic C–H bonds of propylene are oxidized prior to the formation of CC bonds due to thermodynamic limitations. − Some attempts have been made to improve the selectivity of PO, such as adding a cocatalyst to the Ag catalysts or changing the supports. − Some improvements in PO selectivity have been obtained through these measures, but they are not sufficient for industrial-scale applications.…”