Toward a Paradigm Shift in Low‐Temperature SCR Catalyst Design: Defect Engineering and Data‐Driven Integration

Low‐temperature selective catalytic reduction (SCR) technology is essential for controlling nitrogen oxide (NOx) emissions in nonpower sectors. However, conventional vanadium‐based catalysts have insufficient de‐NOx activity at low temperature and pose environmental toxicity issues, which significantly limits their application. Transition metal oxides have attracted considerable attention due to their excellent low‐temperature catalytic performance. Nonetheless, precisely tuning their active sites to achieve both high activity and high selectivity remains a critical and urgent challenge. This work systematically reviews the key factors influencing the performance of low‐temperature NH 3 ‐SCR based on reaction mechanism. The mechanism and challenges of defect engineering strategies, such as oxygen vacancies (OVs), heteroatom doping, crystal facet exposure, and surface reconstruction, in controlling both activity and selectivity were analyzed. The potential of data‐driven methods was explored for revealing the multiscale mapping relationship of “composition‐structure performance,” guiding defect construction and across‐scale optimization. This review offers cutting‐edge theoretical guidance for designing novel low‐temperature de‐NOx catalysts with both high activity and high selectivity, providing new insights for shifting catalyst design paradigm.