Bimetallic MxRu100−x nanoparticles (M = Fe, Co) on supported ionic liquid phases (MxRu100−x@SILP) as hydrogenation catalysts: Influence of M and M:Ru ratio on activity and selectivity

Bimetallic FexPt100–x Nanoparticles Immobilized on Supported Ionic Liquid Phases as Hydrogenation and Hydrodeoxygenation Catalysts: Influence of the Metal Content on Activity and Selectivity

“…In this case, together with 43% of the product 1d , a large amount of products with saturated ring 1c (14%) and 1e (43%) was formed. Since Pt ensembles are responsible for ring hydrogenation as it was observed for Fe 20 Pt 80 @SILP and Pt 100 @SILP, this result indicated that it might be difficult to achieve a controlled formation of bimetallic Fe 40 Pt 60 NPs on unmodified silica support, in agreement with previous observations. ,, …”

“…Eventually, HDO of 1a and 1c can also be observed, typically using multifunctional catalytic systems possessing acidic functionalities. ,, Figure b shows conversions and product yields as a function of the Pt content in Fe x Pt 100– x NPs, where all the reactions were performed under identical conditions ( T = 175 °C, p­(H 2 ) = 50 bar, t = 16 h, solvent - heptane). Monometallic Fe@SILP did not show any activity under these conditions, consistent with previous observations . Increasing the Pt content in Fe 80 Pt 20 @SILP resulted in 34% conversion with 1a (30%) as a major product.…”

“…Interestingly, for bimetallic Fe x Pt 100– x @SILP catalysts, the formation of intermediate 1b was never observed, indicating a decrease in the rate of the aromatic ring hydrogenation upon the addition of Fe. A similar behavior was previously observed with other bimetallic catalysts (e.g., FeRu, CoRu, and CoRh) − and can be attributed to the absence of ensembles of 3–4 adjacent noble metal atoms required to hydrogenate 6-membered aromatic rings. , …”

“…Briefly, the silane-functionalized IL [1-butyl-3-(3-triethoxysilylpropyl)­imidazolium]­NTf 2 [NTf 2 = bis­(trifluoromethane)­sulfonimide] was chemisorbed on dehydroxylated SiO 2 by silanization with a loading of 0.7 mmol g –1 . The synthesis of bimetallic Fe x Pt 100– x NPs (with x = 100, 80, 60, 50, 40, 20, and 0) was achieved by adapting an organometallic approach developed by our groups for bimetallic FeRu, CoRu, and CoRh@SILP. − This approach involved the decomposition of the metal precursors {Fe­[N­(Si­(CH 3 ) 3 ) 2 ] 2 } 2 and [Pt 2 (dba) 3 ] (dba = dibenzylideneacetone) in situ in the presence of the SILP material under H 2 (3 bar) at 150 °C for 18 h with a mixture of anisole and tetrahydrofuran as a solvent to ensure a good solubility of both precursors (total metal loading = 0.35 mmol g –1 ) (Figure ). {Fe­[N­(Si­(CH 3 ) 3 ) 2 ] 2 } 2 and [Pt 2 (dba) 3 ] were used since they possess similar decomposition rates.…”

“…Based on an organometallic approach for the assembly of nanoparticles on molecularly modified surfaces, our groups reported recently the versatile synthesis of Fe x Ru 100– x , Co x Ru 100– x , and Co x Rh 100– x NPs on supported ionic liquid phase supports (SILPs). The application of these M1 x M2 100– x @SILP materials in catalysis evidenced the remarkable influence of the nature of the “diluting” 3d metal M1 and its relative ratio to the noble metal M2 on the overall hydrogenation performance. − In particular, synergistic effects were observed for the hydrogenation of aromatic ketones, with an enhancement of CO hydrogenation activity for bimetallic NPs, while aromatic ring hydrogenation was completely stopped for specific metal ratios.…”