Catalytic activities of Mo-modified Ni/Al2O3 catalysts for thioetherification of mercaptans and di-olefins in fluid catalytic cracking naphtha

Fe-Promoted Ni/Al2O3 Thioetherification Catalysts with Enhanced Low-Temperature Activity for Removing Mercaptans from Liquefied Petroleum Gas

“…As shown in Figure a, the intensities of the decomposed peaks of the NiS x and NiS­(FeS) species were both enhanced. The fitted peaks located at 855.2 and 855.9 eV are assigned to the coexisting NiO and NiFe 2 O 4 phases, respectively, , due to the incomplete sulfidation at lower sulfiding temperature Table also lists the respective contributions of the different Ni species in the three sulfided NiFe/Al 2 O 3 catalysts, and as compared with the results for 14Ni/Al 2 O 3 , increasing the Fe 2 O 3 loading from 4 to 12 wt % gave rise to an increase in the overall percentage of the sulfided Ni species from 18.9% to 32.0%, indicating that the presence of Fe 2 O 3 has a dramatic promoting effect on the sulfidation degree of Ni in the NiFe catalyst system.…”

“…The characteristic peaks of Ni 2p 3/2 and Ni 2p 1/2 are accompanied by shakeup satellites at binding energies of about 861.7 and 880 eV, corresponding to charge-transfer transitions . As shown in Figure a, the XPS spectrum in the Ni 2p 3/2 region of the 14Ni/Al 2 O 3 sample can be fitted to two peaks centered at 855.2 and 856.5 eV, attributed to Ni 2+ present in the octahedral positions of the supported NiO phase and Ni 2+ in the tetrahedral sites of NiAl 2 O 4 phase formed by the reaction of NiO and Al 2 O 3 , respectively. , With increasing Fe 2 O 3 loading, the Ni 2p 3/2 peak of the bimetallic NiFe catalysts exhibits a slight blue shift compared with that of 14Ni/Al 2 O 3 , and the Ni 2p 3/2 binding energy is decreased to 855.4 eV for 14Ni8Fe/Al 2 O 3 , indicating the enhanced electron density of the nickel oxide species due to the addition of Fe 2 O 3 to 14Ni/Al 2 O 3 . Some researchers have observed an additional fitting peak at around 855.7 eV corresponding to Ni 2+ in the NiFe 2 O 4 phase , that coexists with the isolated NiO phase in NiFe catalyst systems.…”

“…The sulfided monometallic Ni catalyst and the bimetallic NiFe catalysts were also characterized by XPS, and the spectra of the Ni 2p 3/2 region were deconvoluted into the contribution of the different Ni species; the results are presented in Figure a. For the sulfided monometallic Ni/Al 2 O 3 catalyst, a distinct peak with a binding energy of 852.7 eV was observed as compared to its oxidic precursor, corresponding to NiS x species generated from the NiO phase, whereas fitted peaks corresponding to NiO (∼855.1 eV) and NiAl 2 O 4 (∼856.5 eV) , coexist for the sulfided sample. The respective proportions of the different Ni species in the sulfided 14Ni/Al 2 O 3 catalyst are listed in Table .…”

“…7 For this reason, Bouchy et al 8 developed a NiMo catalyst system and found that the bimetallic NiMo catalyst had much higher activity for both the transformation of mercaptans and the selective hydrogenation of diolefins at 160 °C. Shen et al 9 reported that Mo-modified Ni/Al 2 O 3 catalysts also resulted in improved selectivity for diolefin hydrogenation and reduced polymerization of diolefins to form coke in the FCC naphtha thioetherification process, but the reaction temperature was also as high as 160 °C.…”

Thioetherification of isoprene and butanethiol on transition metal phosphides

“…Although solid acid catalysts (sulfonic acid resin, intercalate compound, solid phosphoric acid and BF 3 treated γ -Al 2 O 3 ) are efficient for the thioetherification, they are easily deactivated by basic nitrogen species in FCC gasoline [4] . Widely applied in Prime-G + processes, sulfided Mo-Ni/Al 2 O 3 is more active and stable than sulfided Ni/Al 2 O 3 [5,6] because of the promotion of Mo that modifies the electronic and structural properties of Ni [6] . The thioetherification mechanism on sulfided Mo-Ni/Al 2 O 3 was proposed [7] .…”