Spatially Separated NO Capture and Hydrogenation for NH 3 Synthesis from O 2 -Containing Streams
Year: 2026
Type: preprint
Abstract: The selective conversion of nitric oxide (NO) in combustion flue gases to ammonia (NH 3 ) is a promising strategy for sustainable nitrogen management. However, this conversion remains challenging in O 2 -containing exhaust gases because coexisting O 2 strongly inhibits catalytic hydrogenation. Here, we developed a tandem NO capture and hydrogenation system for NH 3 production from O 2 -containing streams. Various adsorbents were examined for NO capture in the presence of O 2 , and Li-impregnated β zeolite with 1.2 wt% Li, denoted as Li(1.2)/β, was selected as a representative adsorbent owing to its high NO x adsorption capacity. In situ IR spectroscopy showed that NO x species formed from NO + O 2 on Li(1.2)/β were mainly present as [NO + ][NO 2 ] adducts, which subsequently desorbed as NO 2 upon heating. By coupling the Li(1.2)/β-based temperature-swing adsorption unit, operated between 30 and 200 °C, with a downstream Cu(5)/CeO 2 hydrogenation reactor operated at 450 °C, the tandem system maintained an NH 3 yield of 55–60% during a 7 h cyclic operation. These results demonstrate the feasibility of spatially separated NO capture and downstream NO x hydrogenation for converting NO in O 2 -containing streams into a valuable nitrogen resource.
Source: ChemRxiv
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223152340