Advanced flue gas purification for household heating: Evaluating CuO-based and Pt–Pd-based catalysts under real and simulated operating conditions

Biomass combustion offers a renewable and decentralised source of thermal energy; however, it remains a major contributor to local air pollution, particularly carbon monoxide (CO) and organic gaseous compounds (OGC). This study evaluates the performance of a CuO-based monolithic catalysts (CH-03 to 07) and compares it to a commercial Pt–Pd-based reference catalyst (CAT 1) under both artificial flue gas (AFG) and real flue gas (RFG) conditions. Tests included controlled AFG conditions containing CO, OGC and water vapour, as well as RFG conditions during wood briquettes and bioethanol combustion, accounting for thermal cycling and sulphur exposure. Under AFG conditions, CH-04 achieved CO conversion rates close to CAT 1 (64 ± 2.3% vs. 70 ± 2.2 % at ∼370 °C) and demonstrated hydrothermal stability with reversible performance drops below 10 % in the presence of steam. CH-07 matched CAT 1 in OGC conversion but showed up to 27 % lower CO conversion. During bioethanol combustion experiments, catalyst CH-04 exhibited resilience to sulphur content. However, under wood combustion, CH-04 experienced progressive deactivation (conversion drop from 61 % to 22 %) despite regeneration attempts, while CAT 1 maintained stable conversion (84–95 %). These results support the future potential of CuO-based catalysts as low-cost alternatives in low-sulphur applications, while highlighting the need for further development to enhance durability under harsh operating conditions.