Influence of W on the reduction behaviour and Brønsted acidity of Ni/TiO2 catalyst in the hydrogenation of levulinic acid to valeric acid: Pyridine adsorbed DRIFTS study

Effects of Solid Acid Supports on the Bifunctional Catalysis of Levulinic Acid to γ‐Valerolactone: Catalytic Activity and Stability

“…TiO 2 is widely adopted as a practical oxide support to synthesize efficient heterogeneous catalysts used for the LA conversion. [46] Suitable metal dispersions and preferred acid sites can be offered by TiO 2 , which are propitious to obtain satisfactory GVL selectivity. [47] The catalytic performance of widely used TiO 2 supported metal catalysts with different metals including Ni, Pt, Pd and Ru was tested.…”

“…[8a,62] Although the stronger acidity of these molecular sieves could achieve a rapid transformation of LA, the GVL selectivity was found to decrease dramatically when a prolonged time and an elevated temperature were applied, which could be potentially ascribed to the fact that the intensive energy input provided an equilibrium shift from GVL to VA with pentenoic acid as an intermediate via cascade processes containing a ring-opening step and a subsequent hydrogenation step. [46,63] A complete LA conversion and high GVL yield of 91% was given over the Ru/H-β at 473 K within 4 h ( Table 2, entry 23), whereas the Ru/TiO 2 could only lead to a markedly lower LA conversion of 57.8% within the same time, and the GVL selectivity of Ru/H-β reduced from 91% to 86.6% with an extended time of 10 h. [13] A 75.3% GVL yield could be delivered at 250°C over a 30 wt % Ni/H-ZSM-5 catalyst, and a remarkable decreased GVL selectivity of 63% was observed when the temperature was raised to 295°C (Table 2, entry 27). [64] Actually, the reduced GVL selectivity was mainly attributed to the over-conversion of GVL to valeric acid (VA) under enhanced conditions.…”

Transformation of Levulinic Acid to Valeric Biofuels: A Review on Heterogeneous Bifunctional Catalytic Systems

“…Although precious‐metal‐based catalysts supported on acidic materials are widely adopted in the synthesis of VAEs and exhibit desirable catalytic activities, high costs caused by the large use of precious metals, such as Pt, Pd, and Ru, may greatly limit their further industrial application. Accordingly, research into developing novel nonprecious‐metal‐based bifunctional catalysts has received extensive attention in recent years . As an active component of commonly used nonprecious‐metal catalysts for many hydrogenation processes, cobalt is usually regarded as an excellent substitute for precious metals .…”

Selective Hydrogenolysis of Furfural Derivative 2‐Methyltetrahydrofuran into Pentanediol Acetate and Pentanol Acetate over Pd/C and Sc(OTf)3 Cocatalytic System

“…1,4‐PDO was mainly obtained from the hydrogenation of LA and GVL . Heterogeneous catalyst systems mainly included noble catalysts like Pt–Mo/HAP, Ru–Re/C, Rh‐Mo/SiO 2 , Ir–MoO x /SiO 2 , Ru/C, and non‐noble metal catalysts like Cu/ZrO 2 ‐OG, Cu–TiO 2/ ZrO 2 ‐CP‐600, Ni/TiO 2 . Homogeneous catalysts included Ru‐based catalysts, Co‐based catalysts, and Fe‐based catalysts .…”

“…[19] Heterogeneous catalysts ystems mainly included noblec atalysts like Pt-Mo/HAP, [20] Ru-Re/C, [21] Rh-Mo/SiO 2 , [22] Ir-MoO x /SiO 2 , [23] Ru/C, [24] and non-noblem etal catalysts like Cu/ZrO 2 -OG, [25] Cu-TiO 2/ ZrO 2 -CP-600, [26] Ni/TiO 2 . [27] Homogeneous catalysts included Rubased catalysts, [28] Co-based catalysts, [29] and Fe-based catalysts. [30] Dumesic and co-workersr eported the conversion of methyltetrahydrofuran by using Rh-ReO x /C into 2-pentanol, but the conversion rate was low under these reaction conditions.…”