Tin‐Based Mesoporous Silica for the Conversion of CO₂ into Dimethyl Carbonate

Abstract

Sn-based SBA-15 was prepared by reacting di-n-butyldimethoxystannane with SBA-15 pretreated with trimethylchlorosilane (TMCS) to cap the external hydroxyl groups. Small-angle X-ray diffraction (SXRD), infrared spectroscopy (IR), nitrogen adsorption/desorption, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and inductively coupled plasma atomic emission (ICP-AES) measurements allow us to propose that the organotin species are located within the pore channels of the mesoporous host. This novel material catalyzes selectively the coupling of CO(2) with methanol to dimethyl carbonate (DMC). The reaction time-conversion dependence shows that a turnover number (TON) of 16 can be reached at 423 K under 20 MPa, which is among the highest reported so far in the absence of water traps. Moreover, as the catalytic activity is retained after recycling, even higher values can be obtained on a cumulative basis. A further TON increase is observed with the reaction temperature. Interestingly, the tin-based SBA-15 mesoporous material exhibits lower TONs if the TMCS pretreatment is left out. Therefore, the organotin species located outside the channels are far less active than those located within.

Greener synthesis of dimethyl carbonate using a novel ceria–zirconia oxide/graphene nanocomposite catalyst

“…The general procedure for preparation of supported catalysts involve the transformation of the precursors into the required active compound and the deposition of the active compound onto the support surface. Different materials have been widely used as suitable catalyst supports in recent studies; these includesilica [34][35], molecular sieve [36],complex supports [31], metal oxides [37],graphene oxide (GO), activated carbon and multi-walled carbon nanotubes [38].…”

Supported Porous Nanomaterials as Efficient Heterogeneous Catalysts for CO2 Fixation Reactions

“…It is interesting to note that other basic, acidic and amphoteric metal oxides like γ‐Al 2 O 3 , TiO 2 , ZrO 2 , MgO, and Y 2 O 3 showed much lower activity for this CO 2 fixation reaction on N ‐methyl aminoethanol under identical reaction conditions (160 °C reaction temperature, 7 bar CO 2 pressure in the presence of a large excess of ethanol). Grafting of Sn IV at the surface of 2D‐hexagonal SBA‐15 resulted Sn‐SBA‐15 material that can directly convert a methanol and CO 2 mixture under high pressure and temperature to dimethylcarbonate (Table ) …”

“…have employed MCM‐41/HMS‐type ordered mesoporous silica materials as catalysts for the direct fixation of CO 2 to N , N′ ‐dimethylethylene diamine to obtain 1,3‐dimethyl‐2‐imidazolidinone under supercrital CO 2 conditions . An Sn‐containing mesoporous silica material (Sn‐SBA‐15) has shown good reactivity (TON=16.0 at 423 K temperature under 20 MPa pressure) for the synthesis of dimethyl carbonate (DMC) in the coupling of CO 2 and methanol under high CO 2 pressure . Although, the synthesis of DMC from CO 2 can proceed under much lower CO 2 pressure in the presence of supported metallic nanoparticles, this post synthetic functionalization route for grafting of Sn IV over highly ordered 2D‐hexagnonal mesoporous silica has its own advantage of utilizing surface acidity of the catalyst.…”

“…Grafting of Sn IV at the surface of 2D-hexagonal SBA-15 resulted Sn-SBA-15 material that can directly convert am ethanol and CO 2 mixture under high pressure and temperature to dimethylcarbonate (Table 1). [142]…”

“…[184] An Sn-containingm esoporous silica material (Sn-SBA-15) hass hown good reactivity (TON = 16.0 at 423 Kt emperature under 20 MPa pressure) for the synthesis of dimethyl carbonate (DMC) in the coupling of CO 2 and metha- nol under high CO 2 pressure. [142] Although, the synthesis of DMC from CO 2 can proceed under much lower CO 2 pressure in the presence of supported metallicn anoparticles, this post synthetic functionalization route for graftingo fS n IV over highly ordered 2D-hexagnonal mesoporous silica has its own advantage of utilizing surfacea cidity of the catalyst. Li and co-workers have dispersed g-C 3 N 4 nanoparticles and layerso ver the mesopore channels of SBA-15 materialt oo btain an anocomposite material, which on further impregnationw ith Zn II and Fe III resulted in an efficient catalyst for the oxidative cycloaddition of styrene to 4-phenyl-1, 3-dioxolan-2-one.…”