Electrocatalytic conversion of biomass-derived oxygenated aromatics to cycloalkanes

Electrocatalytic hydrotreatment (ECH) was explored as a mild technique to convert oxygenated aromatics, present in oils derived from the deconstruction of lignocellulosic biomass or lignin, into cycloalkanes. Producing cycloalkanes in a one-pot system, as envisioned in the present study, requires that both hydrodeoxygenation and aromatic ring saturation occur electrocatalytically. Thus, an activated carbon cloth-supported ruthenium and platinum (RuPt/ACC) electrocatalyst was synthesized and used to conduct model compound ECH studies to determine substrate conversion, product yields, and faradaic efficiency, enabling the derisking of the electrocatalytic process. The effects of electrocatalyst composition and aromatic ring substituents on cycloalkane yield were examined. Furthermore, ECH of side products and probable intermediates was conducted to map reaction sequences and pathways. Finally, ECH of a 4-O-5 dimer model compound was conducted to study the electrocatalytic cleavage of recalcitrant interunit linkages in lignin. Electrocatalytic transformation of oxygenated aromatics to cycloalkanes on activated carbon cloth-supported ruthenium and platinum under mild conditions (≤60°, atmospheric pressure) using hydrogen equivalents produced in situ by water splitting.