Surface synergistic effect in well-dispersed Cu/MgO catalysts for highly efficient vapor-phase hydrogenation of carbonyl compounds

Abstract

The highly efficient vapor-phase selective hydrogenation of carbonyl compounds (e.g. furfural (FAL) and dimethyl 1,4-cyclohexane dicarboxylate (DMCD)) to corresponding alcohols was achieved excellently over well-dispersed MgO-supported copper catalysts (Cu/MgO), which were prepared by an alternative separate nucleation and aging step method. The characterization results revealed that the structure and catalytic performance of as-formed Cu/MgO catalysts were profoundly affected by the Cu loading. Especially, the results confirmed that the decrease in the Cu loading could lead to the improvement of metal dispersion and the formation of more surface strong Lewis basic sites. In the vapor-phase selective hydrogenation of FAL to furfuryl alcohol (FOL) and DMCD to 1,4-cyclohexane dimethanol (CHDM), two Cu/MgO catalysts with the Cu loadings of 27.6 wt % and 70.9 wt % exhibited superior catalytic performance with the higher conversions (> 97.3%) and selectivities to alcohols (>96.0 %) to other supported ones. The high efficiency of as-formed Cu/MgO catalysts was mainly attributed to the surface synergistic catalytic effect between catalytically active metallic copper species and Lewis basic sites, which held the key to hydrogenation reaction related to the hydrogen dissociation and the activation of carbonyl groups.

Distinct Promotive Effects of 1,8‐Diazabicyclo[5.4.0]undec‐7‐ene (DBU) on Polymer Supports in Copper‐Catalyzed Hydrogenation of C=O Bonds

“…In this context, Mn, Fe, Co, Ni, Cu, and Zn complexes have been utilized for catalytic hydrogenation of unsaturated bonds, especially in carbonyl compounds, as modeled after a number of matured Ru complexes . In addition, (supported) metal particles based on Fe and Cu have emerged as an active area of research.…”

Solvothermal synthesis of CuO–MgO nanocomposite particles and their catalytic applications

“…On the other hand, peaks at 934.2 and 954.1 eV with its shake-up peaks at 942.2 and 962.3 eV are due to the presence of Cu 2+ species 23,24 . 5d, we observe peaks at 530 and 531eV corresponding to lattice oxygen in MgO and CuO 26 , and adsorbed oxygen on the catalyst surface. 5c demonstrates the presence of Mg 1s peak at 1303.9 eV 25 .…”

“…PHI 5000 Versaprobe II X-ray 6 photoelectron spectrometer (ULVAC-PHI) using Al Kα as X-ray beam was used to understand the effect of catalysis on the oxidation states of the Cu, Mg and O components of the catalyst sample. 4d) 26,27 . Figure 4a shows peaks corresponding to Cu, Mg and O in the XPS spectrum for the sample.…”

Hydrogenation of biomass-derived compounds containing a carbonyl group over a copper-based nanocatalyst: Insight into the origin and influence of surface oxygen vacancies

“…It was reported that the Cu + -Cu 0 synergy in Cu/SiO 2 catalysts could remarkably promote the extent of hydrogenation related to ester groups [19][20][21]. In addition, our groups found that the way that ester molecules interacted with Cu/MgO catalyst could be greatly influenced by the surface acid-base nature of catalysts [22]. In this regard, Cu/ ZnO and Cu/SiO 2 catalysts have been used in selective hydrogenation of DMS to GBL [23,24].…”