Boosting Ag/Al2O3 Catalytic Activity for NOx Removal via C3H6-SCR through Functional TiO2 Support Engineering

作者：Yun Zhong, Yingsheng An, Zidi Yan, Zhi Liu, Tao Shen, Hang Xiao, Yanshuang Zhang, Min Xiao, Yong De Yan, Yunbo Yu, Hong He · 发表于：Environmental Science & Technology · 年份：2025 · DOI：10.1021/acs.est.5c07583 · 被引用次数：4 · 研究领域：Catalytic Processes in Materials Science、Advanced Photocatalysis Techniques、Nanomaterials for catalytic reactions

Alumina supported silver (Ag/Al 2 O 3 ) is considered as a promising catalyst for the selective catalytic reduction of nitrogen oxides with hydrocarbons (HC-SCR). However, its practical implementation remains limited by insufficient catalytic performance. Herein, we present a novel strategy to fabricate a highly efficient Ag/TiO 2 /Al 2 O 3 catalyst utilizing a functional TiO 2 -modified AlOOH precursor. The obtained catalyst demonstrates significantly enhanced catalytic activity, durability, and stability for C 3 H 6 -SCR across a broad temperature range compared to conventional Ag/Al 2 O 3 . The incorporation of TiO 2 strengthens the Ag-support interaction through facilitating electron transfer from Ag to the TiO 2 /Al 2 O 3 support, leading to the formation of highly dispersed Ag n δ+ clusters as the dominant active species. Mechanistic studies reveal that Ag n δ+ clusters effectively accelerate the partial oxidation of C 3 H 6 to reactive enolic species, which in turn trigger a new pathway for NO x reduction via the formation of –CN intermediates. This change in reaction mechanism induced by TiO 2 modification was also confirmed by a lower activation energy barrier for NO x reduction compared to that of Ag/Al 2 O 3 . By simultaneously optimizing both the density of active sites and their intrinsic reactivity, this approach delivers a substantial enhancement in C 3 H 6 -SCR performance, offering new insights into catalyst design for hydrocarbon-SCR applications.