Modification of HDT catalysts of FCC feedstock by adding silica to the kneading paste of alumina support: Advantages and disadvantages

Influence of Ni/Mo Ratio on Structure Formation of Ni–Mo Complex Compounds in NiMo/Al2O3 Catalysts for Selective Diene Hydrogenation

“…The band at 780 nm with a shoulder of about 710−720 nm observed for the NiMo-0.5 catalyst can be attributed to the d− d transitions of octahedrally coordinated Ni 2+ ions in NiMoO 4 . 33,34 The intensity of the band at 780 nm almost does not change for all catalysts. The NiMoO 4 species are considered as precursors of the sulfide NiMoS active phase in hydroprocessing catalysts, which should also have high activity in hydrogenation of diolefins.…”

“…270 nm could be assigned to the O 2− → Mo 6+ ligand−metal CT transition in a polymolybdate-like structure containing Mo Oh ions 30 typical for calcined NiMo/Al 2 O 3 catalysts. 33,34 Ni 2+ ions [O 2− (2p) → Ni 2+ (3d) ligand−metal CT transition] can also contribute to the absorption in the UV region. 35 Bulk NiAl 2 O 4 36 and bulk NiO 37 show strong absorption bands in the region of 240−330 nm.…”

Synthesis of Alumina-Supported RhSn Alloy Nanocatalysts by Using Rh@Sn Core–Shell Nanoparticle Precursors for Toluene Catalytic Hydrogenation

“…22 The enhanced performance of bimetallic alloy catalysts is due to the synergistic effect that tunes the electronic and geometric properties of the active metals to achieve better performance. 23,24 In this work, we report efficient and stable aluminasupported RhSn alloy nanocatalysts for hydrogenation of toluene, where the selection of alumina as supports is based on its readily availability, excellent mechanical properties, and thermal stability 25,26 as well as its wide applications in hydrogenation catalysts. 27,28 First, Rh x @Sn y nanoparticles (NPs) with different Rh/Sn ratios were synthesized by a sequential reduction method and then calcined for 2.0 h at 550 NPs on supports by in situ transformation, which facilitates the systematical studies of the synergistic effect to obtain the optimal performance.…”

“…In this work, we report efficient and stable alumina-supported RhSn alloy nanocatalysts for hydrogenation of toluene, where the selection of alumina as supports is based on its readily availability, excellent mechanical properties, and thermal stability , as well as its wide applications in hydrogenation catalysts. , First, Rh x @Sn y nanoparticles (NPs) with different Rh/Sn ratios were synthesized by a sequential reduction method and then calcined for 2.0 h at 550 °C and H 2 reduced for 3.0 h at 500 °C on alumina to obtain Rh x Sn y /Al 2 O 3 . Rh 1 Sn 0.7 /Al 2 O 3 gives the yield higher than 99% under 0.1 MPa of H 2 and 45 °C for toluene hydrogenation to methylcyclohexane, showing better catalytic performance than Rh/Al 2 O 3 catalysts.…”