(6z) Upgrading Biomass-Derived Platform Chemicals By Electrochemical and Photoelectrochemical Catalytic Oxidation

Conversion of biomass to chemicals and fuels is a potentially viable route to minimize our dependence on unsustainable petroleum resources. However, unlike petrochemicals biomass-derived platform chemicals such as HMF, glycerol, and propylene glycol are typically highly oxygenated and require development of new catalytic processes to tune their functionality. Electrocatalysis is an extremely versatile tool where the reaction activation barriers and product selectivity can be directly regulated by tuning the electrode potential. Additionally, electrochemical methods and analysis give unique insight into complex processes at the electrode/electrolyte interface which would be otherwise unavailable without complex in situspectroscopic techniques. Electrochemical systems also give rise to fuel cells, which transform chemical energy to electricity and can also coproduce valuable chemicals. Finally, electrocatalysis can take advantage of renewable energy sources directly using photoelectrochemical (PEC) cells or indirectly by using renewable electricity to drive reactions.

My doctoral research first investigated the cogeneration of electricity and chemicals in direct alcohol anion-exchange membrane fuel cells (AEMFC) with supported noble metal anode electrocatalysts.^1â??2 It was demonstrated that a propylene glycol-fed AEMFC successfully cogenerated electricity and valuable chemicals on carbon-supported platinum or gold nanoparticles (Pt/C, Au/C). Pt/C was very selective for primary alcohol group oxidation to lactic acid under fuel cell operating conditions, while Au/C gave significant amounts of pyruvic acid, a product that has previously eluded heterogeneous catalytic studies on Au. Product selectivity on Au/C was very sensitive to anode potential. Later, I showed that HMF can be successfully oxidized to FDCA, an important bio-based polymer precursor, on supported bimetallic Pd-Au/C electrocatalysts, and the reaction benefited from a synergistic effect between Pd and Au components.²More recently, we have explored the use of stable nitroxyl radicals including TEMPO as electron mediators for selective oxidation of biomass-derived substrates in electrochemical and PEC reactors. This route opens opportunities to use non-noble metal electrodes and to take advantage of solar energy to drive electrochemical conversions.

Teaching Interests:

My background highlights the diverse benefits of electrochemical systems for the upgrading of biomass-derived chemicals, with unique examples in fuel cells, electrolysis flow reactors, and PECs. Electrocatalysis is a thriving research field with blooming practical applications and importance. As an independent faculty researcher, I will lead an interdisciplinary team to engineer advanced electrochemical materials and systems to meet future needs in energy conversion, production and storage, and sustainable chemical manufacturing as well as develop new curriculum for undergraduate and graduate-level electrocatalysis education.

References:

(1) Chadderdon, D. J. et al., ACS Catal. (2015), 6926â??6936.

(2) Han, X. T. et al., Int J Hydrogen Energy (2014), 19767â??19779

(3) Chadderdon, D. J. et al., Green Chem. (2014), 16 3778â??3786.