Porous thermoelectric materials for energy conversion by thermoelectrocatalysis

Novel uses of thermoelectric (TE) materials as catalyst and catalyst promoters have been reported recently for a variety of applications such as environmental gas mitigation, battery, and photoreduction of nuclear wastewater. TE Seebeck voltage is found to increase the catalytic activities by tens to hundreds of times, and this effect is termed thermoelectrocatalysis. In these uses, the TE materials are in an open-circuit configuration, which is different from the usual closed-circuit configuration in the TE energy generation and cooling devices. A new figure of merit defined as the Seebeck voltage per unit heat loss is proposed for the application of thermoelectrocatalysis. Techniques such as dense bulk porous surface and increased thickness of the TE materials are used for the optimization of the thermoelectrocatalysis of the oxyselenide BiCuSeO for the carbon dioxide hydrogenation reactions.