Experimental study on alkylation of PCl3 for methyl-dichloride phosphine synthesis using mass spectrometry detection

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 495; p. 152915
• Main Authors: Li, Banghao, Lan, Xiaocheng, Wang, Tiefeng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-2024
• Subjects: Free radical reaction; Homogenous catalysis; Mass spectrometry; Methyl-dichloride phosphine; Methyl-dichloride phosphine; Homogenous catalysis; Mass spectrometry; Free radical reaction
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.152915

•An online sampling and MS detection method was developed to study the alkylation of PCl3 with CH4.•The addition of chloromethanes significantly enhanced PCl3 conversion.•The effects of operation conditions on YMDP and SMDP were systematically studied.•Chloromethanes converted into lower chlorinated-methanes and chloro-olefins.
An online sampling and mass spectrometry (MS) detection method was developed to study the alkylation of PCl3 with methane at high temperature for synthesis of methyl-dichloride phosphine (CH3PCl2, MDP), which was a free radical reaction on a millisecond time scale. Through qualitative analysis, the byproducts P4 and chloro-dimethyl-phosphine ((CH3)2PCl, CDMP) were identified, with their formation mechanisms elucidated for the first time. The effects of operation conditions, including temperature, residence time, and types and concentrations of chloromethanes (CH4-xClx, x  = 2, 3, 4), on both MDP yield and selectivity, were systematically investigated. The optimal operation conditions were determined based on MDP yield and selectivity. The addition of chloromethanes significantly enhanced PCl3 conversion. Chloromethanes underwent conversion in the reaction, promoting PCl3 conversion while also continuously converting into lower chlorinated methane derivatives. These results are of great significance for guiding rational industrial process development.