Oxidized nickel sulfide,a catalyst of hydroisomerization of dienes into isoolefins

1.	Selective hydrogenation of piperylene into n-amylenes (300C) on applied nickel sulfide was studied in the pulsed mode. It was found that NiS/SiO2 is more selective than NiS/Al2O3.
2.	Treatment of applied NiS with air at 300–500C oxidizes a significant portion of NiS into NiSO4, which gives the catalyst hydroisomerizing properties and permits obtaining up to 44% isoamylenes from piperylene. In contrast to oxidized NiS/SiO2, oxidized NiS/Al2O3 retains hydroisomerizing activity for a much longer time, which is due to the higher resistance of NiSO4 to reduction on Al2O3 than on SiO2.
3.	The data obtained indicate that reduced nickel atoms are the active sites of selective hydrogenation, while sulfur, sulfide or sulfate, is the surface modifier.

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1477–1482, July, 1989.