Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO2(101) Surface: A Theoretical Investigation. Issue 4 (7th January 2020)

• Record Type: Journal Article
• Authors: Zhao, Yuntao; Zhu, Xinli; Wang, Hua; Han, Jinyu; Mei, Donghai; Ge, Qingfeng
• Is Part Of: ChemCatChem. Volume 12:Issue 4(2020)
• Page Start: 1220
• Page End: 1229
• Publication Date: 2020-01-07
• Subjects: anatase TiO2 -- formaldehyde and acetone -- aldol condensation -- aqueous phase -- DFT; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.201901736
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: A mechanistic understanding of catalytic reactions at solid‐liquid interface is limited both experimentally and theoretically but attracts much interest. Using density functional theory calculations (DFT) and ab initio molecular dynamics (AIMD) simulations, we investigated the effect of liquid water on α‐H abstraction, C−C coupling, and dehydration steps of aldol condensation of formaldehyde and acetone on an anatase TiO2 (101) surface. The existence of the aqueous phase lowered the Gibbs energy of activation of dehydration step pronouncedly from 187 to 74 kJ/mol through proton transfer mechanism, making the hydrogenation pathway more favorable in the aqueous phase. In contrast, a mixed route prevails in the vapor phase. This work provides insights into the effect of the bulk water through a proton transfer mechanism on the dehydrogenation, C−C coupling, and dehydration steps. Abstract : Theoretical Investigation : Our DFT calculations show that the aldol condensation of formaldehyde and acetone to methyl vinyl ketone in the vapor phase follows a mixed pathway of hydrogenation and tautomerization route. The existence of aqueous phase makes the hydrogenation pathway dominate the production of methyl vinyl ketone.