Biomimetic CO oxidation below \u2212100\u2009\xb0C by a nitrate-containing metal-free microporous system

Konstantin Khivantsev,Libor Kovarik,Janos Szanyi,Hristiyan A Aleksandrov,Georgi N Vayssilov,Yong Wang,Miroslaw A Derewinski,Nicholas R Jaegers

doi:10.1038/s41467-021-26157-3

Abstract

CO oxidation is of importance both for inorganic and living systems. Transition and precious metals supported on various materials can oxidize CO to CO2. Among them, few systems, such as Au/TiO2, can perform CO oxidation at temperatures as low as −70 °C. Living (an)aerobic organisms perform CO oxidation with nitrate using complex enzymes under ambient temperatures representing an essential pathway for life, which enables respiration in the absence of oxygen and leads to carbonate mineral formation. Herein, we report that CO can be oxidized to CO2 by nitrate at −140 °C within an inorganic, nonmetallic zeolitic system. The transformation of NOx and CO species in zeolite as well as the origin of this unique activity is clarified using a joint spectroscopic and computational approach.

Highlights

CO oxidation is of importance both for inorganic and living systems
In the 1980s, it was first discovered with Raman spectroscopy that NO+ species can form in Na-zeolites upon exposure to NO and O2 or NO29
Hadjiivanov and coworkers’ pioneering studies using FTIR spectroscopy and isotopic methods on NxOy molecules[10,11,12] established, that NO+ can form in H-ZSM-5 upon interaction with NO and O2 mixture

Summary

Introduction

CO oxidation is of importance both for inorganic and living systems. Transition and precious metals supported on various materials can oxidize CO to CO2. Living (an) aerobic organisms perform CO oxidation with nitrate using complex enzymes under ambient temperatures representing an essential pathway for life, which enables respiration in the absence of oxygen and leads to carbonate mineral formation. To mitigate harmful CO emissions, inorganic materials such as transition- or noble metals supported on solid materials are capable of oxidizing CO at elevated temperatures[1,2]. Among such systems, Au nanoparticles supported on e.g., titania, discovered by Haruta, represents a material class active for CO oxidation at temperatures as low as −70 °C, the lowest presently known[1]. A pathway for CO oxidation by nitrate in a completely inorganic, non-metallic crystalline solid (zeolite SSZ-13, CHA) is disclosed which is reactive at temperatures below −100 °C

Methods

Results

Conclusion