Distinguishing Dynamic Phase Catalysis in Cu based nanostructures under Reverse Water Gas Shift Reaction

Abstract

Increasing anthropogenic carbon dioxide (CO$_2$) emissions have led to rising global temperatures and climate change. Using earth-abundant metal-oxide catalysts such as Cu$_2$O for reducing CO$_2$ through RWGS reaction seems lucrative. In this work, we have used Cu$_2$O nanostructures and identified its activity, stability, and selectivity for reducing CO$_2$ to carbon monoxide (CO) which can be further hydrogenated to higher hydrocarbons using Fisher Tropsch synthesis. We have observed that the rate of CO$_2$ conversion increases by 4 times and significantly drops at 300 C where the catalyst was reduced to metallic Cu and the rate increases slightly as the temperature is further increased. The selectivity of CO$_2$ reduction is majorly towards CO with a trace amount of methane. We can further exploit the Mie resonance characteristics of Cu$_2$O nanocatalysts and in-situ generation of hydrogen for hydrogenation of CO$_2$ to enhance the activity of the catalysts. We can further identify the optimum size and shape of the nanocatalysts required and use hybrid nanostructures which can favor RWGS reaction thus improving the stability of these catalysts.