The Support Effects on the Direct Conversion of Syngas to Higher Alcohol Synthesis over Copper-Based Catalysts

Abstract

The types of supports employed profoundly influence the physicochemical properties and performances of as-prepared catalysts in almost all catalytic systems. Herein, Cu catalysts, with different supports (SiO2, Al2O3), were prepared by a facile impregnation method and used for the direct synthesis of higher alcohols from CO hydrogenation. The prepared catalysts were characterized using multiple techniques, such as X-ray diffraction (XRD), N2 sorption, H2-temperature-programmed reduction (H2-TPR), temperature-programmed desorption of ammonia (NH3-TPD), X-ray photoelectron spectroscopy (XPS) and in situ Fourier-transform infrared spectroscopy (FTIR), etc. Compared to the Cu/Al2O3 catalyst, the Cu/SiO2 catalyst easily promoted the formation of a higher amount of C1 oxygenate species on the surface, which is closely related to the formation of higher alcohols. Simultaneously, the Cu/Al2O3 and Cu/SiO2 catalysts showed obvious differences in the CO conversion, alcohol distribution, and CO2 selectivity, which were probably originated from differences in the structural and physicochemical properties, such as the types of copper species, the reduction behaviors, acidity, and electronic properties. Besides, it was also found that the gap in performances in two kinds of catalysts with the different supports could be narrowed by the addition of potassium because of its neutralization to surface acidy of Al2O3 and the creation of new basic sites, as well as the alteration of electronic properties.

Effect of KCoMoS2 Catalyst Structures on the Catalytic Performance of Higher Alcohols Synthesis via CO Hydrogenation

“…Moreover, the higher alcohols, after separation and purification, can serve as feed stocks for value-added fine chemicals, demonstrating a wide application prospect [4]. Generally, the catalytic production process for higher alcohols synthesis from syngas needs to occur over the solid catalysts, which are roughly classified into the following four categories: modified methanol synthesis catalysts [5,6], modified Fischer-Tropsch synthesis catalysts [7,8], noble metal ruthenium-based catalysts [9,10], and molybdenum sulfide-based catalysts [11,12]. Among these catalyst systems, the modified methanol synthesis catalyst mainly produced methanol with a lower C 2+ OH selectivity.…”

Selective catalytic oxidation of NH3 into N2 during biogas combustion over 2 wt%PdO/5 wt%CuO/γ-Al2O3

“…3b, H 2 -TPR profile of CuO/Al 2 O 3 (before test) reveals the presence of a reduction peak at 300 °C corresponding to the reduction of CuO. After test, we noticed a decrease in the intensity of this peak at 300 °C and the formation of another two reduction peaks at 600 °C and 800 °C approximately which correspond to the reduction of CuAl 2 O 4 and CuAlO 2 respectively [28]. Such incorporation of copper into the support lattice can be due to high interaction between CuO and alumina at high temperature.…”

Rational Design of Non-Precious Metal Oxide Catalysts by Means of Advanced Synthetic and Promotional Routes

“…In light of the above aspects, the present Special Issue is mainly focused on the fabrication and fine-tuning of NMs-free metal oxide catalysts by means of advanced synthetic and/or promotional routes. It consists of fourteen high quality papers, involving: a comprehensive review article on the recent advances on the rational design and fine-tuning of ceria-based metal oxide catalysts [5]; two articles on the ceria nanoparticles morphological effects on N 2 O decomposition [14] and CO oxidation [10] over ceria-based binary oxides; two articles on NO decomposition over K-promoted Co-Mn-Al mixed oxides [34,35]; one article on the effect of ceria synthesis methods on the carbon pathways in dry reforming of methane (DRM) over Ni/CeO 2 catalysts [36]; one article on the impact of synthesis procedure and aliovalent doping in Co-Al spinel-type oxides for lean methane combustion [37]; one article on the support effect on the direct conversion of syngas to higher alcohols over copper-based oxides [38]; one article on nanofibrous Ni/Al 2 O 3 catalysts prepared by electrospinning for methane partial oxidation [39]; one article on the influence of precursor compounds on the selective catalytic reduction (SCR) of NO x by NH 3 over FeMgO x oxides [40]; one article on the synthesis and active sites determination of ZrO 2 -supported WO x solid acid catalysts [41]; one article on the synthesis and electrocatalytic performance of RuO 2 nanoparticles [42]; one article on the fabrication and photocatalytic performance of mesoporous frameworks of ZnFe 2 O 4 (ZFO) and MnFe 2 O 4 (MFO) nanoparticles [43]; and one article on the synthesis of polymer supported catalysts for arylamination reaction [44].…”

“…X. Li et al [38] reported on the impact of support nature (SiO 2 , Al 2 O 3 ) and alkali promotion (K) on the synthesis of higher alcohols from CO hydrogenation over Cu-based catalysts. Significant differences on CO conversion and product's selectivity were revealed, attributed to support-and alkali-induced effects on redox and electronic properties.…”