Research Update: April 2016

Graph Abs_BMM

Brian’s recent article published in the Journal of Catalysis elucidates the reaction mechanism for methyl lactate dehydration to acrylic acid (and esters) over zeolite NaY. Expanding on our previous work covering ion exchange between adsorbed molecules and zeolites (Topics in Catalysis 2015), we show that Brønsted acid sites can be generated in-situ on the catalyst surface via interactions with water, and are subsequently the primary active sites for the desired dehydration pathway. The dissociative adsorption of methyl lactate to form adsorbed sodium lactate and a surface methyl group is the key branching point between the dehydration (desired) and decarbonylation (undesired) pathways, as undissociated methyl lactate rapidly reacts to acetaldehyde over Brønsted acid sites. The mechanistic level understanding of the active sites and species involved in this key reaction will allow for the rational design of new catalytic systems.