Epicatalytic thermal diode: Harvesting ambient thermal energy

Abstract

A simple device is introduced that utilizes the phenomenon of epicatalysis to establish a stationary temperature difference by which ambient environmental thermal energy might be converted into useful work. This epicatalytic thermal diode (ETD) maintains temperature differentials between two closely spaced parallel plates housing a chemically active gas and transports heat up its own temperature gradient. In 2014 a rudimentary ETD demonstrated stationary, epicatalytically-derived temperature differentials in excess of 120 K. In 2016 room-temperature epicatalysis was demonstrated, raising hope for room-temperature ETDs. This technology appears to be scalable, and potential applications include direct heating, cooling, and thermoelectric power generation. This article explores the ETD through analytic and numerical modeling. ETDs appear capable of sustaining temperature differences in excess of 200 K in isothermal, room-temperature environments and generating thermal energy flux densities in excess of 106 W/m2, which might translate to thermoelectric power densities up to several times 104 W/m2. Laboratory-testable, room-temperature ETDs are proposed.