Elucidation of sulfidation state and hydrodesulfurization mechanism on ruthenium–cesium sulfide catalysts using 35S radioisotope tracer methods

Oxide/polymer interfaces for hybrid and organic solar cells: Anatase vs. Rutile TiO2

“…Among these, materials are semiconductor oxides like TiO 2 or ZnO [33,34], specifically, TiO 2 is employed as an active support for trapping S-containing impurities [33][34][35][36][37][38][39][40][41]. Experimental work supported by density functional calculation, STM and synchrotron studies, among others, have shown that thiophene can be bond to TiO 2 via the aromatic ring, but also by the S-end atom [37][38][39][40][41]. Among all of these studies, and more related to our research work, is the interaction of thiophene with stoichiometric TiO 2 and defective TiO 2 À x rutile [38].…”

Transition Metal Sulfide Catalysts for Petroleum Upgrading – Hydrodesulfurization Reactions

“…They reported that the location of cesium is close to ruthenium species, the dispersion of ruthenium species increases with an increase in the Cs/Ru ratio and furthermore the presence of cesium in close proximity to ruthenium atoms strengthens the bond of ruthenium and sulfur stabilizing ruthenium sulfide. In later works (Ishihara et al, 1998(Ishihara et al, , 2003, they elucidated the behaviour of sulfur on the ruthenium catalysts and the role of cesium in HDS by radioisotope tracer methods, concluding that the mobility of sulfur on the catalysts decreased by the addition of cesium. On the contrary, the amount of labile sulfur on the catalyst increased with the amount of cesium added and reached the maximum at Ru:Cs=1:2 suggesting that Ru species in the catalyst was successfully dispersed on alumina.…”

“…The addition of NaOH did not improve the HDS reaction because of the poisoning of some sites. Nonetheless, a cesium-promoted Ru catalyst with Ru/Cs molar ratio of 1:2 exhibited HDS activities comparable to that of conventional Co-Mo catalyst (Ishihara et al, 2003). The insertion of atoms like cesium seems to enhance the number of labile sulfur atoms, aids to stabilize the RuS2 active phase as it strengths Ru-S bond of ruthenium sulfide, promotes the C-S bond scission of dibenzothiophene (DBT) and therefore the catalytic activity increases (Ishihara et al 2004).…”