Fig. 4: Mechanisms A, B, C, and D of CO oxidation by HNO3 in H-CHA.
From: Biomimetic CO oxidation below −100 °C by a nitrate-containing metal-free microporous system
Zeolite structures Zeo1 and Zeo2 differ by the different locations of the zeolite proton at basic O centers from the AlO4 unit. The first species given after Zeo1 and Zeo2 are the one which interacts with the zeolite proton. Corresponding energy diagrams of the investigated mechanisms (Mechanisms A, B, C, and D) for CO oxidation by HNO3 in H-CHA. The corresponding structures are also shown. Shorter names are used for the structures in the energy diagrams with respect to the schemes above as: IS – Zeo1/CO/HNO3; FS – Zeo1/CO2/HNO2; IC – Zeo2/NO2+/HCO2−; ID – Zeo2/HCO2−/NO2+, FS2 – Zeo2/CO2/HNO2. Color coding: Si – blue, O – red, Al – green, N – light blue, C – brown, H – white.
