The coal slime-derived zeolite-supported Ru catalyst for ethylene hydroesterification

Ethylene hydroesterification is an important carbonyl synthesis reaction that allows the production of corresponding esters from CO, alcohols, and olefins, achieving 100% atom efficiency. This study reports a Ru-based catalyst supported on a catalytic carrier material derived from flotation coal tailings, which demonstrates excellent catalytic performance in the methoxycarbonylation of ethylene to produce methyl propionate (MP). The molecular sieve prepared from the flotation coal tailings has a cubic structure, and the rich folds and grooves on its surface provide excellent anchoring sites for loading Ru nanoclusters. This structure allows better fixation of Ru metal clusters and promotes strong metal-support interactions. After loading 2% Ru, the catalyst exhibits the best catalytic performance. The acidic sites on the molecular sieve provide more protonic acid sites, which facilitate the formation of Ru-H species and enhance the dissociative activation of ethylene via a reverse hydrogen spillover mechanism. This leads to a significant increase in the generation rate of reaction intermediates, thereby improving the catalytic activity. The use of waste flotation coal to prepare molecular sieves achieves waste recycling, with a green and simple preparation process. Furthermore, the results of this study offer new insights for future research on olefin hydroesterification and hydroformylation, as well as other carbonyl synthesis reactions.