Water electrolysis is a frontrunner technology for production of carbon-neutral hydrogen. Conventional electrolysis generates H2 at the cathode and O2 at the anode of an electrochemical cell. Replacement of the slow anodic OER with alternative reactions has been proposed as a way to both lower energy input and increase the value proposition with co-products. This talk will explore oxidation chemistries that replace the OER and can co-generate H2 at the anode, often at very low cell voltage. This scenario is possible when the anode reactant possesses hydrogen moieties with higher chemical potential than H2—spontaneous catalytic hydrogen production is well-known from aldehyde substrates, for example. During (electro)oxidation of these compounds, control over chemical (pure thermally driven) vs. electrochemical steps allows for adsorbed hydrogen moieties (H*) formed in the process to preferentially desorb from the electrode by recombination (H*+H*--&gt;H2) rather than by discharge (H*--&gt;H++e-), which occurs in conventional electrolysis. Such “electrochemically-assisted dehydrogenation” (EAD) can ideally consume just 1e-/mol H2 for aldehyde-to-acid reactions. While the prospect of forming hydrogen at both electrodes is intriguing, there are also kinetic and thermodynamic limits to be considered. We will discuss recent results from our lab probing the mechanisms of EAD and provide analysis of the constraints on such reactions for process intensification of electrolysis.

Electrochemically-assisted dehydrogenation and prospects for “anodic hydrogen”

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.