Unconventional Electrocatalytic Deuteration of Organic Molecules

Deuterated molecules play important roles in pharmaceutical research because the replacement of hydrogen atoms by deuterium atoms can provide unique properties, such as altered metabolic pathway, longer stability, increased half-life, and reduced clearance. However, the utilization of deuteration in pharmaceutical research still faces many challenges because of the limited versatile and inexpensive deuteration methods. This project will investigate novel electrocatalytic methods for the effective deuteration of organic molecules under ambient conditions (room temperature and atmospheric pressure). This project will not only advance the integration of electrochemistry in organic synthesis but also build the talent pool of future research scientists in the emerging field of organic electrocatalysis. The research work will also be leveraged with a myriad of outreach activities to educate the public about the emerging transition to a greener chemical industry. The outcomes of the research will also enrich a new class in Green Chemistry and Sustainability. The Sun group at the University of Cincinnati will design, develop, and understand innovative electrocatalytic systems for the efficient deuteration of organic model compounds using deuterated water (D2O) as the deuterium source. Different from conventional electrocatalytic deuteration which takes place at the cathode while reactants and products are both dissolved in the electrolyte, the synthesis strategy will enable the deuteration reactions to take place in a separate chamber outside of the electrochemical cell, taking advantage of the unique deuterium absorption and permeation property of palladium membrane electrodes. Deuterated water will be split in an electrolysis cell. The deuterium species will then permeate through the palladium reactor to the exterior surface of the membrane. By developing various co-catalysts coated on the palladium membrane electrodes, the project will aim to realize the efficient deuteration of a large group of organic molecules, ranging from alkenes, aldehydes, ketones, halides, to amino acids. The proposal's reactor concept takes advantage of the catalytic hydrogenation and hydrogen absorption properties of the palladium membrane. The main strength is the reactor concept which takes the electricity driven splitting of D2O to provide the deuterium source under low voltage input and under ambient conditions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.