A RuCl₃ complex catalytic system for hydroesterification of ethylene, carbon monoxide, and ethanol

Abstract

CO, ethylene, and CH3CH2OH can be converted to ethyl propionate by ethylene hydroesterification. The RuCl3 complex catalytic system (RuCl3‐DMF‐NaI‐NaOH) is reported for ethylene hydroesterification in this paper. The function mechanisms of each substance of the catalytic system have been analyzed. The catalytic activity of RuCl3 is increased by DMF (N,N‐dimethylformamide) as the ligand. The formation of 3‐pentanone is prevented by NaI by accelerating the termination rate at which ethyl attacks the propionyl species, while the formation of acetal is inhibited by NaOH. The formation mechanism of ethyl propionate has been analyzed. In‐depth researches have been done on the reaction temperature, catalyst concentration, and other factors influencing the performance of catalytic system. In RuCl3‐DMF‐NaI‐NaOH catalytic system, at reaction conditions (180°C, P(C2H4) = P(CO) = 1.5 MPa), after 4 h reaction, the conversion of ethylene reaches 87.1% with 92.8% selectivity of ethyl propionate. This work provides a neoteric catalytic system for the synthesis of ethyl propionate by ethylene hydroesterification.