Integrated DFT and experimental study on Co3O4/CeO2 catalyst for direct synthesis of dimethyl carbonate from CO2

• Published in: Journal of CO2 utilization Vol. 67; p. 102323
• Main Authors: Kulal, Nagendra, Bhat, Soumya S., Hugar, Vithobha, Mallannavar, Chaitra N., Lee, Seung-Cheol, Bhattacharjee, Satadeep, Vetrivel, Rajappan, Shanbhag, Ganapati V.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2023
• Subjects: CeO2; CO2; Dimethyl carbonate; Methanol; Nanorods; CeO2; Dimethyl carbonate; Nanorods; CO2; Methanol
• ISSN: 2212-9820; 2212-9839
• DOI: 10.1016/j.jcou.2022.102323

The oxygen deficient site on the catalyst has a strong impact on the activation of CO2 for the synthesis of dimethyl carbonate (DMC). The Co3O4/CeO2 catalyst exhibits multiple reduction behavior as cobalt metal species differ in the strength of their interaction with CeO2. This causes the surface reduction from Ce4+ to Ce3+ in solid solution Co-O-Ce. The dispersion of Co3O4 enhanced the formation of oxygen deficient site as revealed by XPS, CO2-chemisorption and TPR. The non-precious Co3O4/CeO2 nanorod was recognized as a potential catalyst for promoting Ce4+ to Ce3+ for CO2 activation and dimethyl carbonate synthesis (81.5% of yield). Energetics of oxygen vacancy formation of low index surfaces of CeO2 was determined with first-principles calculations based on DFT. Results disclosed the Ce4+ to Ce3+ formation energy of CeO2 due to Co substitution and corroborated the experimental results. Further, calculations provide the details of the effect of Co substitution on the electronic structure of reduced CeO2 surfaces. Estimated CO2 adsorption energy indicates (110) as the most active surface for activation of CO2. [Display omitted] •Promoting CO2 activation in DMC synthesis by Co incorporation in CeO2 catalyst.•Reduction in oxygen vacancy formation energy of CeO2 due to Co doping by DFT.•Influence of CeO2 morphology on CO2 adsorption capacity and product yield.•Co/CeO2 gave 81.5% of DMC yield more than CeO2 due to increase in oxygen vacancy.•Catalyst versatility in one pot synthesis of DMC using epoxide, CO2 and methanol.