SOLID-STATE ELECTROCATALYTIC OXIDATION OF METHANOL VAPOR

The ruthenium analogue of Prussian blue, a ruthenium oxide crosslinked and anchored by cyanoruthenates, is a good solid electrolyte and redox conductor at ambient temperatures. The system can also be easily incorporated into a common anion exchange membrane. When the material is investigated, either as a thin film or in the composite membrane, the redox transitions involving oxygen transfer, probably from structural water, and producing ruthenium in oxidation state IV or higher, are accessible, even in voltammetry without external electrolyte. We have successfully utilized two-electrode and three-electrode solid-state electrochemical cells to sense methanol by catalytic oxidation of the vapor at the gas/solid interfaces.