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Correlation of urea precipitation temperature with phase formation, morphology, and catalytic activity for CO2 conversion of CeO2
Author(s)
Duangtanon, Jenjira
Sreemueang, Chanakan
Noppharat, Phetchphalin
Kulthananat, Tachatad
Srinives, Sira
Kim-Lohsoontorn, Pattaraporn
Date Issued
August 1, 2025
Type
Article
Abstract
This study proposes a simple method for tailoring the morphology and activity of cerium oxide (CeO2) catalysts in converting carbon dioxide (CO2) and methanol to green organic carbonate, dimethyl carbonate (DMC), to utilize and reduce CO2 emissions. CeO2 was prepared by urea precipitation at 85, 105, and 125 °C for 2 h, then calcining at 600 °C for 2 h. The phase structure and morphology of CeO2 correlated with the urea hydrolysis rate. A low degree of supersaturation at 85 °C led to heterogeneous precipitation of cerium oxycarbonate (Ce2O(CO3)2.H2O) and CeO2 with spherical morphology, while a higher degree of supersaturation at 105 °C and 125 °C resulted in homogeneous precipitation of single-phase Ce2O(CO3)2.H2O with spindle and elongated octahedral morphology, respectively. The spindle-shaped CeO2 prepared at 105 °C with a predominant surface (111) facet showed the highest catalytic activity, with a DMC yield of 18.81 mmol.gcat−1. The enhanced catalytic efficiency of spindle-shaped CeO2 was due to the high concentration of surface-active defect sites of exposed cerium cations and oxygen vacancies, which optimized the number of acid–base sites in adsorbing and activating CO2 and methanol to produce DMC.
Citation
Research on Chemical Intermediates, 51(8), 4103-4128, 2025