Synthesis of dimethyl carbonate from CO₂ and methanol over a hydrophobic Ce/SBA-15 catalyst

Abstract

A series of Ce/SBA-15 catalysts with different degrees of hydrophobicities were prepared via a post-grafting method and used for the direct synthesis of dimethyl carbonate (DMC) from CO 2 and methanol. The Ce/ SBA-15-6 catalyst exhibited the highest DMC yield of 0.2%, which was close to the equilibrium value under the reaction conditions of 130 C, 12 h and 12 MPa. The catalysts were characterized via XRD, BET, FT-IR, solid-state 29 Si MAS NMR, CA, TEM, XPS and NH 3 /CO 2 -TPD; the results indicated that the hydrophobicity of the catalysts facilitated the creation of oxygen vacancies, which could act as Lewis acids to activate methanol. Higher amounts of moderate acid sites led to higher yields of DMC. In addition, the hydrophobicity of the catalysts could also reduce the adsorbed water on their surface and increase the DMC yield while shortening the reaction time.

Metal-organic frameworks MOF-808-X as highly efficient catalysts for direct synthesis of dimethyl carbonate from CO2 and methanol

“…6. It could be clearly seen that the DMC formation rates were basically in accordance with the order of the number of acidic and basic sites on MOF-808-X, and MOF-808-4, with the largest number of acidic and basic sites, exhibited the best activity, indicating that the higher number of acidic and basic sites are favorable for enhancing the catalytic performance, which is consistent with our previous results [14,15,24] and those reported by Tomishige et al [9] and Lee et al [49−51].…”

“…For the synthesis of DMC from CH3OH and CO2, many catalysts have been developed. Among the reported heterogeneous catalysts such as ZrO2 [8][9][10], CeO2 [11,12], CexZr1-xO2 [13], FexZr1-xOy [14], ZrO2/SBA-15 [15], Al2O3/CeO2 [16], CexZr1-xO2/grapheme [17], [EMIM]Br/Ce0.5Zr0.5O2 [18], and Cu-Ni/ZrO2 [19]. Zr-based metal oxide catalysts have attracted much attention owing to their excellent stability as well as high selectivity towards DMC.…”

Co–Ce Oxides Supported on SBA-15 for VOCs Oxidation

“…The O2-TPD, H2/ TPR (Temperature-programmed reduction,) and C3H8/TPR experiments were performed in order to obtain information regarding the adsorptive and reductive properties of the catalyst. The selected temperature range is close to the one used According to literature [15,16], Ce 4+ and Ce 3+ are present together, although the kind of cerium salt used as precursor and the treatment atmosphere can affect the relative concentration.…”

“…The sample marked with Co:Ce(1:0.5) shows only Ce 3+ oxidation state indicating that the decrease in Ce concentration stabilizes Ce 3+ on the surface. According to literature [15,16], Ce 4+ and Ce 3+ are present together, although the kind of cerium salt used as precursor and the treatment atmosphere can affect the relative concentration.…”

Effect of Cobalt Doping on the Stability of CaO‐Based Catalysts for Dimethyl Carbonate Synthesis via the Transesterification of Propylene Carbonate with Methanol

“…In addition, DMC is also widely used as a fuel oil additive due to its high oxygen content (53 %) [4] and employed as a key solvent in the synthesis of commodity polymers [5] . There are several routes for producing DMC, such as the oxidative carbonylation of methanol, [6] direct synthesis from CO 2 and methanol, [7,8] methanolysis of urea, [9] and transesterification of cyclic carbonate (propylene carbonate or ethylene carbonate) with methanol [10,11] . Therefore, DMC synthesis via the transesterification of propylene carbonate (PC) with methanol under mild conditions is a clean catalytic route eliminating the use of toxic and corrosive reagents and is recognized as a promising and environmentally benign route for DMC.…”