High-Performance Na-CH₃ONa/γ-Al₂O₃ Catalysts for High-Efficiency Conversion of Phenols to Ethers

Abstract

An efficient alkaline catalyst with a porous structure (Na-CH 3 ONa/γ-Al 2 O 3 ) was prepared by the melting method. The wastewater from the semicoke plant (WW SCP ) was extracted multiple times with isometric dimethyl carbonate (DMC)–cyclohexane mixed solvent at room temperature to obtain an organic phase (OP) with a high concentration of phenols. Ether (OPCP) was obtained by catalytic conversion of OP over catalyst Na-CH 3 ONa/γ-Al 2 O 3 at 210 °C and with a reaction time of 2.5 h. Both OP and OPCP were analyzed with a gas chromatograph/mass spectrometer (GC/MS) and a quadrupole Exactive Orbitrap mass spectrometer (QPEOTMS). The results showed that only DMC, phenol, o -cresol, and other monohydric phenols were detected in OP, and only other saturated ethers such as anisole and O -methylanisole were detected in OPCP. Through the study of the catalytic conversion of the WW SCP -related model compound, it was found that Na-CH 3 ONa/γ-Al 2 O 3 could effectively activate (deprotonate) phenol into phenate, and the strong nucleophilic oxyanion of phenate would attack the methyl carbon and carbonyl carbon on DMC to obtain methyl and methoxy groups. Thereby, phenate can be combined with methyl and methoxy groups to acquire the product anisole. In addition, the catalyst Na-CH 3 ONa/γ-Al 2 O 3 was found to still have high catalytic activity after 10 repeated cycles. It was speculated that this was related to the abundant microporous and mesoporous structure of the catalyst Na-CH 3 ONa/γ-Al 2 O 3 .

Selective O-alkylation of Phenol Using Dimethyl Ether

“…In Figure 1, the pure γ-Al2O3 support showed three broad peaks at 37.07°, 45.89°, and 66.7°, corresponding to the (131), ( 040), (044) (COD no. 96-154-1583), respectively [14]. The γ-Al2O3 support showed well-resolved diffraction peaks, which were well-matched to γ-Al2O3 (JCPDS 10-0425), suggesting presence of an amorphous framework, which is appropriate for impregnation [15].…”

Separation and Analysis of Oxygen-Containing Compounds in a Shaanxi Middle/Low-Temperature Coal Tar

“…However, unknown structural details of complex heteroatom-containing species mixtures cannot be revealed by these analytical methods. In high-resolution mass spectrometry, an FT Orbitrap MS (quadrupole exactive orbitrap mass spectrometer) with an electron spray ionization source (ESI/FT Orbitrap MS) is more affordable compared with a Fourier transform ion cyclotron resonance MS, and it is of a higher resolving power (140,000) than time-of-flight MS. − Therefore, combining GC–MS with ESI/FT Orbitrap MS makes good sense of fully realizing the compositions of SPs in coal tar.…”