Catalytic Conversion of High Fructose Corn Syrup to Methyl Lactate with CoO@silicalite-1

Abstract

Methyl lactate (MLA), a versatile biomass platform, was typically produced from the catalytic conversion of high-priced fructose. High fructose corn syrup (HFCS) is a mixture of glucose, fructose, water, etc., which is viewed as an economical substitute for fructose to produce MLA due to the much lower cost of separation and drying processes. However, the transformation of HFCS to MLA is still a challenge due to its complex components and the presence of water. In this work, the catalytic conversion of HFCS to MLA over CoO@silicalite-1 catalyst synthesized via a straightforward post citric acid treatment approach was reported. The maximum MLA yield reached 43.8% at 180 °C for 18 h after optimizing the reaction conditions and Co loading. Interestingly, adding extra 3% water could further increase the MLA yield, implying that our CoO@silicalite-1 catalyst is also capable for upgrading wet HFCS. As a result, the costly drying process of wet HFCS can be avoided. Moreover, the activity of CoO@silicalite-1 catalyst can be regenerated for at least four cycles via facile calcination in air. This study, therefore, will provide a new opportunity to not only solve the HFCS-overproduction issues but also produce value-added MLA.