Mechanistic Studies of Continuous Glucose Upgrading over Lewis Acidic Silicates by Operando UV–Vis and HSQC NMR

Lewis acidic silicates are effective catalysts for the conversion of glucose to bio-molecules of industrial interest, such as methyl lactate and methyl vinyl glycolate. Although well studied in recent years, open questions of these processes remain, particularly in regard to elements of the reaction mechanisms and how the catalysts deactivate during continuous operation. Such questions endure because of the lack of spectroscopic techniques capable of providing insights into the catalytic reaction at operational conditions. In this study, we follow the catalytic conversion of glucose over the Lewis acidic silicates Sn-Beta and Hf-Beta in a continuous flow reactor equipped with operando UV–vis spectroscopy. In doing so, we identify several transient absorption features related to the activation and conversion of glucose at various operational conditions (