Synthesis of diethyl carbonate from ethyl carbamate and ethanol over ZnO-PbO catalyst

Synthesis of diethyl carbonate from urea and ethanol over lanthanum oxide as a heterogeneous basic catalyst

“…Clearly, the preparation method has an important impact on the surface basicity of La 2 O 3 , which is strongly correlating with the catalytic activity. Zinc-containing catalysts were used frequently in the alcoholysis of urea to produce dimethyl/diethyl carbonate [1,24]. We also evaluated the catalytic activity of commercial ZnO under the same reaction conditions.…”

“…Obviously, the DEC yield is close to that of La 2 O 3 -500 catalyst. However, the zinc-containing catalyst was prone to form homogenous coordinates of Zn(NCO) 2 (NH 3 ) 2 and leached into the liquid phase of the reaction system [1], which is unfavorable for the practical application as a heterogeneous catalyst. In the subsequent investigations, the effect of preparation conditions on the catalytic performance of La 2 O 3 catalyst was studied in detail.…”

“…Diethyl carbonate (DEC) is an important organic intermediate, which is recognized as an environmentally benign chemical because of its negligible eco-toxicity and low bioaccumulation [1][2][3]. DEC has good reactivity due to the active groups of ethoxy and carbonyl in its molecular structure.…”

Incorporation of CO2 into carbonates through carboxylation/hydration reaction

“…ZnO‐PbO was found to be an efficient catalyst in the synthesis of DEC from ethyl carbamate and ethanol. Lead and Zn(NCO) 2 (NH 3 ) 2 derived from ZnO‐PbO were considered to be the real active composition for DEC synthesis . ZnO‐Fe 2 O 3 catalyst prepared by the thermal decomposition of layered double hydroxides was also applied for the synthesis of DEC from ethyl carbamate and ethanol, and XRD patterns revealed that the calcination temperature was an important factor for catalytic performance.…”

“…The results suggested that both Zn(C 3 H 6 O 3 ) and NH 4 Cl, which formed during the reaction, functioned as essential ingredients for the carbonylation of glycerol. In detail, NH 4 Cl plays a role in activating glycerol and Zn(C 3 H 6 O 3 ) in activating urea . Very recently, the same group reported that the high catalytic activity of Zn(OAc) 2 in carbonylation of glycerol and urea could be ascribed to the in situ formation of Zn(NH 3 ) x (OAc) 2 .…”