Epoxidation of styrene with NaOCl and catalyzed by nickel(II) complexes

Epoxidation of styrene was catalyzed by some nickel(II) complexes, with NaOCl as the oxygen donor. The catalyst Ni(PA)(2). 2H(2)O has been found to be stable for the epoxidation of styrene. Some additives were introduced in the reaction to improve the "micro-environment" of the catalyst. Radical trap had little influence on styrene epoxidation. It was interesting to find that phase-transfer agent had negative influence on epoxidation in this biphase reaction. A possible mechanism of styrene epoxidation catalyzed by Ni(PA)(2). 2H(2)O has been proposed.

Partial oxidation of ethane to syngas over nickel-based catalysts modified by alkali metal oxide and rare earth metal oxide

The catalytic activity, thermal stability and carbon deposition of various modified NiO/gamma-Al2O3 and unmodified NiO/gamma-Al2O3 catalysts were investigated with a flow reactor, XRD, TG and UVRRS analysis. The activity and selectivity of the NiO/gamma-Al2O3 catalyst showed little difference from those of the modified nickel-based catalysts. However, modification with alkali metal oxide (Li, Na, K) and rare earth metal oxide (La, Ce, Y, Sm) can improve the thermal stability of the NiO/gamma-Al2O3 and enhance its ability to suppress carbon deposition during the partial oxidation of ethane (POE). The carbon deposition contains graphite-like species that were detected by UVRRS. The nickel-based catalysts modified by alkali metal oxide and rare earth metal oxide have excellent catalytic activities (C2H6 conversion of similar to 100%, CO selectivity of similar to 94%, 7x 10(4) l/(kg h), 1123 K), good thermal stability and carbon-deposition resistance.