Effects of Basic Promoters on the Catalytic Performance of Cu/SiO2 in the Hydrogenation of Dimethyl Maleate

Abstract

Continuous hydrogenation of dimethyl maleate (DMM) toγ-butyrolactone (GBL), 1,4-butanediol (BDO) and tetrahydrofuran (THF) is a promising process in industry. In this study, Cu-M/SiO2 catalysts modified by basic promoters (M = Mg, Ca, Sr, Ba, La) were prepared, and characterized by physical adsorption of N2, in situ XRD, H2-TPR, CO2-TPD. With the addition of basic promoters, the basicity of Cu-M/SiO2 catalysts was improved. The particle size of CuO on Cu-M/SiO2 catalyst was increased after modified by Mg, Ca, Sr, Ba. However, the CuO particle was decreased on the Cu-La/SiO2 catalyst. The series of Cu-M/SiO2 catalyst was applied to the hydrogenation of DMM. The addition of basic promoters increased the selectivity of GBL during the hydrogenation for the basic promoters improved the dehydrogenation of BDO to GBL in alkaline sites. Furthermore, Cu-La/SiO2 presented a higher activity in the hydrogenation of DMM, due to its higher dispersion of Cu.

A Review on the Conversion of Synthetic Gas to LPG over Hybrid Nanostructure Zeolites Catalysts

“…Evaluating different kinds of catalyst supports and active sites are highly required to further enhance the process performance and LPG production, inserting promoters to the bifunctional catalyst is one of the good options. [116,117] The effect of Ca addition as a promoter had been evaluated by Ma et al ( 2012), [118] on CuÀ ZnÀ Al/IEÀ PdÀ Y. They reported that the used of Ca at specific amount enhanced the stability of the catalyst without affecting its activity.…”

“…Evaluating different kinds of catalyst supports and active sites are highly required to further enhance the process performance and LPG production, inserting promoters to the bifunctional catalyst is one of the good options [116,117] . The effect of Ca addition as a promoter had been evaluated by Ma et al.…”

Highly Active and Efficient Cu@SiO2 Catalyst: Enabled Nucleophilic and Electrophilic Activation of Active Methylene Compounds

“…The presence of a band at 462 cm À 1 corresponds to the bending vibrations of Cu-OH groups present in Cu@SiO 2 . [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53] The scanning electron microscopy (FE-SEM) analysis depicted in Figure 2 compares the morphological topography of SiO 2 and 4 wt % Cu@SiO 2 catalyst. Due to the excess use of ammonia, the reaction medium becomes basic, and under such conditions, the gel particles tend to make Stöber silica particles appear spherical-shaped (Figure 2(A).…”

“…Remarkably, numerous reports on texture, structure, and catalytic activity exist. The catalyst was synthesized by sol‐gel, deposition precipitation, ammonia evaporation, impregnation, loading, and urea‐assisted gelation method etc., (Supporting Information, Table S3) [35–54] . Some of them have demonstrated different catalytic performance, such as cross‐coupling reactions of aryl/alkyl thiols with aryl halides, reduction of furfural to 2‐methyl furan, oxidation of alcohols, and cyclization to tetrahydrofuran synthesis.…”

“…Unequivocally, the catalyst possesses versatile application in organic transformation. Considering this, our interest is to utilize various AMCs to synthesize high‐value chemicals [39–63] . Herein, we demonstrated that Cu@SiO 2 enabled Knoevenagel condensation, followed by Michael's addition of AMC on carbonyl, halides, and coupling with amines towards Gabapentin intermediates.…”