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A series of bimetallic NixCu(10-x)/SiO2 (where x is the mass fraction of Ni and the total metal loading was fixed at 10 wt%.) catalysts with different Ni/Cu mass ratio are prepared and characterized by X-Ray diffraction (XRD), N2 adsorption-desorption, inductively coupled plasma mass spectrometry (ICP-MS), H2 temperature-programmed reduction (H2-TPR) and transmission electron microscope (TEM). The benzofuran (BF) hydrodeoxygenation (HDO) performance of as-prepared catalysts are evaluated in a fixed flow reactor. The results showed that the incorporation of Cu to Ni/SiO2 catalyst can increase surface area of catalyst and improve the reducibility of nickel oxide species, which contributed to higher catalytic activity and total deoxygenated compounds yield. Moreover, the strong synergistic effect between Ni and Cu led to the formation of NiCu alloy at the Ni mass fraction of 5 wt% and thus induced smaller crystallite size and exposure of more active particles, which inevitably contributed to the improved HDO performance for Ni5Cu5/SiO2 catalyst. At 300 °C, 3.0 MPa, MHSV=3.0 h−1 and H2/oil = 500(v/v), the total yield of deoxygenated products over Ni5Cu5/SiO2 catalyst reached 86.0%, which is increased by 10.8% and 77.4% as compared to those of monometallic Ni/SiO2 (75.2%) and Cu/SiO2 catalysts (8.8%), respectively. Finally, a possible reaction network for HDO of BF on Ni5Cu5/SiO2 catalyst was proposed. [ABSTRACT FROM AUTHOR]

The Cu-based perovskite shows good methanol selectivity but low CO2 conversion in CO2 hydrogenation to methanol. After treated by NaBH4 liquid reduction, perovskite LaCuZn sample (l-LCZ) is reduced partially, particle size becomes smaller and BET surface area increases. This sample (l-LCZ) was tested for CO2 hydrogenation to methanol direct without H2 reduction, and the catalytic activity of it is higher obviously than that over the catalyst LaCuZn which is reduced by H2 at 623 K for 6 h. NaBH4 liquid reduction has good influence on the perovskite properties. [ABSTRACT FROM AUTHOR]

Cu/Zn/Al/Zr catalysts were prepared by liquid reduction method and tested for the synthesis of methanol by CO hydrogenation. With the purpose of relieving the aggregation of reduced Cu species, the order of calcination and liquid reduction process was modified. Catalysts with different thermal treatments were characterized by XRD, N physisorption, TEM, NO chemisorption, TG-MS, XPS, TPR, CO-TPD techniques. When liquid reduction was performed after calcination procedure, metallic Cu specific area and dispersion increased and the interaction among components was strengthened. The modified catalyst displays a slight superiority in CO conversion and methanol selectivity. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Multifunctional catalysts are highly attractive for green oxidation process integrating excellent conversion and selectivity with high separability and recyclability. In this regards, a facile method is developed to fabricate yolk-shell microspheres consisting of FeO cores, mesoporous CeO shells and loaded Pd nanoparticles. Microspheres with 2.6 % Pd loading exemplify excellent catalytic activity for solvent-free, selective oxidation of benzyl alcohol to benzaldehyde by molecular oxygen at 373 K and atmospheric pressure, resulting in 80.5 % conversion of benzyl alcohol with 94.8 % selectivity for benzaldehyde. The catalyst can be magnetically separated and recycled without significant loss of catalytic efficiency even after seven catalytic runs. Graphical Abstract: [ABSTRACT FROM AUTHOR]

A series of La-Mn-Zn-Cu-O based perovskite ceramic precursors were prepared and characterized by XRD, N-adsorption, SEM, H-TPR, NO-adsorption, XPS and TPD techniques. Both LaCuO and LaMnO perovskite structures were observed for the materials and more defects and the 'metal-on oxide' can be realized via reduction. It was found that the samples with both LaCuO and LaMnO structures showed better catalytic performance for methanol synthesis from CO/H. Higher methanol selectivity might due to the appearance of Cu that derived from the abundant defects of perovskite structure. The ratio of both Cu and Cu species to the total copper species was the significant factor for the CO conversion. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The uniform Pd nanoparticles were immobilized on the surface of spinel-type ZnAlO support for Suzuki-Miyaura coupling reactions. High-surface-area ZnAlO support with microporous framework was successfully synthesized utilizing concurrent hexamethylenetetramine hydrolysis and homogeneous coprecipitation induced spontaneously under solvothermal conditions. The obtained support Pd catalyst was used as heterogeneous and recyclable catalyst for the Suzuki-Miyaura coupling reaction in an environmentally friendly ethanol solvent under ligand-free ambient conditions, and exhibited excellent catalytic activity. The remarkable catalytic activity is attributed to the homogeneous distribution of small Pd nanoparticles on the ZnAlO matrix as well as the strong metal-support interaction. Furthermore, the catalytic activity did not deteriorate after recycling for five times, suggestive of the good stability of the catalyst. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The highly-dispersed copper-based catalysts for the gas-phase hydrogenation of dimethyl oxalate to ethylene glycol (EG) were prepared from a Cu-Zn-Al layered double hydroxide (LDH) precursor. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N adsorption-desorption, H temperature programmed reduction (H-TPR) and H-NO titration indicated that the composition, texture, and structure of resulting copper-based catalysts were profoundly affected by the calcination temperature of LDH precursor. Moreover, the as-synthesized catalyst calcined at 600 °C was found to exhibit a superior catalytic hydrogenation performance with an EG yield of 94.7 % to the other catalysts calcined at 500 and 700 °C, which should be mainly attributed to the presence of the highly-dispersed active metallic copper species over metal oxide matrix. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A novel catalyst preparation method aimed to a slurry reactor has been suggested. Its main innovative thought lies in preparing the slurry catalysts directly from solution. Activity tests indicate that the CuO–ZnO/Al2O3 catalyst prepared by the novel method can efficiently catalyze syngas to DME and the selectivity to DME reaches 93.08%. The catalyst shows a good stability during the reaction of 440 h. [ABSTRACT FROM AUTHOR]