US EPA

7427768 

Journal Article 

Fabrication and characterization of ZrO2 and ZrO2/SiO2 catalysts and their application in the synthesis of methyl N-phenyl carbamate: a study of the reaction mechanism by using in situ FT-IR spectroscopy 

Li, F; Jia, Y; Jia, A; Gao, L; Wang, Y; Wang, Z; Xue, W 

2021 

1 

Reaction Kinetics, Mechanisms and Catalysis
ISSN: 1878-5190 

Springer Science and Business Media B.V. 

132 

2 

893-906 

English 

10.1007/s11144-021-01949-2 

WOS:000620460100003 

http://://WOS:000620460100003
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The reaction of dimethyl carbonate (DMC) and aniline for the synthesis of methyl N-phenyl carbamate (MPC) over ZrO2/SiO2 catalyst was investigated. ZrO2/SiO2 showed the higher catalytic performance than that of ZrO2 because of the formation of Zr–O–Si bond, which increased the proportion of weak acid sites on the surface of ZrO2/SiO2 catalyst, and the weak Lewis acid sites were in favor of MPC synthesis. Furthermore, the reaction of DMC and aniline over ZrO2/SiO2 catalyst was studied by in situ Fourier transform infrared spectroscopy (FT-IR). When aniline adsorbed on catalyst, aniline lost protons of −NH2 to the surface O atom in Zr–O–Zr. As for DMC, there were two coordination mode of DMC with Zr4+ and the monodentate coordination by the carbonyl oxygen atom with Zr4+ was in the majority. The formation of MPC might be due to the nucleophilic attack on the carbonyl C atom of DMC by the N atom of adsorbed aniline after removing methanol. When the adsorbed aniline attacked the C atom on the methyl group of DMC, N-methylaniline (NMA) and monomethyl carbonate (MMC) was formed. MMC was unstable, and then the adsorbed methanol formed after removing CO2. © 2021, Akadémiai Kiadó, Budapest, Hungary. 

Aniline; Dimethyl carbonate; Methyl N-phenyl carbamate; Reaction mechanism; ZrO2/SiO2 catalyst; Aniline; Atoms; Catalysts; Fourier transform infrared spectroscopy; Methanol; Silicon; Zirconia; Carbonyl oxygen atoms; Catalytic performance; Dimethyl carbonate; Fabrication and characterizations; Fourier transform infra red (FTIR) spectroscopy; Monodentate coordination; Nucleophilic attack; Reaction mechanism; Silicon compounds