Trimetallic Cu–Ni–Zn/H-ZSM-5 Catalyst for the One-Pot Conversion of Levulinic Acid to High-Yield 1,4-Pentanediol under Mild Conditions in an Aqueous Medium

Abstract

The one-pot direct conversion of levulinic acid (LA) to 1,4-pentanediol (1,4-PDO) was investigated over a trimetallic Zn-promoted Cu–Ni alloy on a H-ZSM-5 (Cu–Ni–Zn/H-ZSM-5) catalyst. Under mild reaction conditions at 130 °C and a H2 pressure of 2.5 MPa for 6 h in an aqueous medium, almost complete conversion of LA to high-yield 1,4-PDO (93.4%) was achieved. The presence of the Zn promoter effectively suppressed the growth of the Cu–Ni alloy nanoparticles (NPs) on the surface of H-ZSM-5. Consequently, the reducibility of the Cu–Ni–Zn alloy was much higher than that of the Cu–Ni alloy. The numerous Lewis acid sites of the Cu–Ni–Zn/H-ZSM-5 catalyst enhanced the adsorption of LA, and the adsorbed LA was converted to γ-valerolactone (GVL) at the Brønsted acid sites of H-ZSM-5 followed by hydrogenation at the Cu–Ni alloy sites. Subsequently, the readsorption of GVL was activated at the Lewis acid sites and GVL underwent ring opening, followed by hydrogenation to form 1,4-PDO at the Cu–Ni alloy sites. The H2 spillover on the Zn-promoted Cu–Ni alloy NPs enhanced the hydrogenation of LA to 1,4-PDO. Because of the mild reaction conditions, the formation of coke and active site sintering was highly suppressed. In addition, metal leaching did not occur over the trimetallic Cu–Ni–Zn/H-ZSM-5 catalyst. Consequently, the Cu–Ni–Zn/H-ZSM-5 catalyst could be used for up to five cycles with minimal activity loss.

Enhanced Hydrogenation of Levulinic Acid over Ordered Mesoporous Alumina‐Supported Catalysts: Elucidating the Effect of Fabrication Strategy

“…In Figure 3a, all the catalysts showed peaks in the ranges 852.20–852.50 eV and 853.90–854.80 eV, which are assigned to Ni° and Ni 2+ (NiAl 2 O 4 and NiO x ), respectively. Further, in Figure 3b, the peaks at the range of 932.10–933.20 eV were ascribed to metallic Cu (Cu 0 ) [36–38] . The observed shifts to higher and lower binding energies (Bes) of the Ni (from 852.15 to 852.50 eV) and Cu species (from 933.15 to 932.10 eV) for Ni−Cu−OMA indicated a more effective charge transfer from Cu to Ni, and further confirmed the formation of the Ni−Cu alloy species.…”

“…Further, in Figure 3b, the peaks at the range of 932.10-933.20 eV were ascribed to metallic Cu (Cu 0 ). [36][37][38] The observed shifts to higher and lower binding energies (Bes) of the Ni (from 852.15 to 852.50 eV) and Cu species (from 933.15 to 932.10 eV) for NiÀ CuÀ OMA indicated a more effective charge transfer from Cu to Ni, and further confirmed the formation of the NiÀ Cu alloy species. Also, the shifts to higher BEs in NiÀ Cu/OMA and NiÀ CuÀ OMA compared with NiÀ Cu/CMA can be associated with the Ni 0 species possessing stronger interaction with their corresponding supports.…”

Layered Double Hydroxide‐Derived Bimetallic Ni−Cu Catalysts Prompted the Efficient Conversion of γ‐Valerolactone to 2‐Methyltetrahydrofuran

“…From another point of view, the interactions between Ni and Cu also have a positive effect on the catalyst's ability to adsorb and activate hydrogen, [43,63,68] which plays a vital role in the catalyst hydrogenation reaction activity. Some researchers have suggested that the introduction of Ni is beneficial for the formation of active Cu−H species, which enhances the H 2 activation ability of catalysts [24] …”

Unravelling the one-pot conversion of biomass-derived furfural and levulinic acid to 1,4-pentanediol catalysed by supported RANEY® Ni–Sn alloy catalysts

“…4,10 A number attempts have been devoted by using copper-based catalysts such as Cu/SiO 2 , 11 Cu/ZnO, 12 skeletal CuAlZn, 13 and Cu-Ni-Zn/H-ZSM-5 (ref. 14) catalysts have been reported to produce high yield of 1,4-PeD (up to 93%). The main drawbacks associated with the Cu-based catalyst systems are due to possible leaching out metal active in aqueous phase system which may suffer the catalyst structure, stability, and its catalytic behaviors.…”