Mixtures of CaO-KOH and CaH2-KOH as solid bases in reactions of interphase transfer

Conclusions The KOH-CaO or KOH-CaH₂ mixtures block the uncatalyzed hydrate transfer of the base in the alkylation reactions with phase transfer reagents.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1799–1801, August, 1987.     

In Situ Radioisotopic Study of the Active Sites of Sulfide CoMo Catalysts and the Mechanism of Thiophene Hydrodesulfurization

The mechanism of thiophene hydrodesulfurization over sulfide catalysts for hydrotreating and the effect of the catalyst composition and feed on the number, distribution, and performance of active sites were studied using ³⁵S and ³H isotopes. Based on the results of radioisotopic study, a method for systematic testing–monitoring of sulfide Co(Ni)Mo catalysts for hydrotreating is developed. The method involves the evaluation of the fraction of the active phase surface occupied by SH groups and the ratio between the concentrations of the surface SH groups and coordinatively unsaturated sites including functioning vacancies. General conditions for the formation and functioning of active sites are formulated on the basis of the monitoring data. Criteria for evaluation of the catalyst performance under conditions of hydrodesulfurization of various kinds of crude are proposed. The results of the pilot tests of commercial catalysts suggest that the criteria proposed are suitable.