Biomimetic CO Oxidation Below – 100 ⁰C by a Nitrate-Containing Metal-Free Microporous System

CO oxidation is of importance both for organic and inorganic systems. Transition and precious metals on various supports can oxidize CO to CO2. Among them, few systems, like Au/TiO2, can perform CO oxidation at the low temperature of -70 ⁰C. Living (an)aerobic organisms perform CO oxidation with nitrate using complex enzymes under ambient temperatures which is an important pathway of their living cycle that enables them to “breathe”/produce energy in the absence of oxygen and leads to the carbonate mineral formation. Herein, we report that CO can be oxidized to CO2 by nitrate at –140 ⁰C in completely inorganic system (zeolite) without metals. The transformation of NOx and CO species in zeolite as well as the origin of this unique activity (catalyzed by Bronsted acid sites) are clarified using spectroscopic and computational approach.