Synergistic Role of Micropore Structure and N/O Dual Functional Groups in Enhancing Low-Temperature NH₃-SCR Denitration over Activated Carbon Catalysts: Structural Evolution and Mechanistic Insights

Ammonia Selective Catalytic Reduction (NH₃-SCR) is highly effective for nitrogen oxide (NO _x ) removal, yet its low-temperature activity remains a key limitation for broader applications. We innovatively synthesized a series of microporous N,O-codoped carbon catalysts (NOAC-x). Results demonstrate that the synergy between catalyst pore structure and surface functional groups governs denitrification performance: Low-temperature calcination induces pore blockage by nitrogen-containing groups (pyridinic N), reducing specific surface area and weakening NH₃/NO adsorption capacity.Moderate calcinatio promotes partial decomposition of nitrogen groups, optimizing the micropore structure while preserving active sites such as carboxyl groups and pyridinic N, thereby significantly enhancing catalytic activity.High-temperature calcinatio triggers pore collapse and decomposition of active groups, degrading performance.NOAC-600 achieved 95% NO _x conversion at 120°C and exhibited merely a 2% activity decline during a 108-hour stability test. This work provides theoretical guidance for designing microporous N,O-dual-doped carbon-based catalysts and underscores the critical importance of micropore structure and surface chemistry optimization in low-temperature SCR technology.