This study investigates the capture of single silver (Ag) atoms on γ-Al₂O₃ through high-temperature-induced crystal plane reconstruction. The "terminal hydroxyl group anchoring mechanism" is utilized to anchor Ag species, with the exposure of different crystal faces of γ-Al₂O₃ controlled by calcination temperature. At 900 °C, the (110) crystal face transforms to the (100) crystal face, increasing the number of terminal hydroxyl groups and facilitating the formation of single-atom Ag dispersions. Experimental results, supported by AIMD and DFT calculations, demonstrate that the (100) surface has more terminal hydroxyl groups than the (110) surface, allowing Ag to exist as single atoms. This results in enhanced catalytic activity and stability in HC-SCR and O₃ decomposition reactions. The study also explores the effect of co-calcination of Ag and γ-Al₂O₃, showing that high-temperature calcination can induce the formation of terminal hydroxyl groups and promote single-atom Ag dispersion. The findings provide insights into designing thermally stable single-atom catalysts by creating additional anchor points for Ag capture at high temperatures.This study investigates the capture of single silver (Ag) atoms on γ-Al₂O₃ through high-temperature-induced crystal plane reconstruction. The "terminal hydroxyl group anchoring mechanism" is utilized to anchor Ag species, with the exposure of different crystal faces of γ-Al₂O₃ controlled by calcination temperature. At 900 °C, the (110) crystal face transforms to the (100) crystal face, increasing the number of terminal hydroxyl groups and facilitating the formation of single-atom Ag dispersions. Experimental results, supported by AIMD and DFT calculations, demonstrate that the (100) surface has more terminal hydroxyl groups than the (110) surface, allowing Ag to exist as single atoms. This results in enhanced catalytic activity and stability in HC-SCR and O₃ decomposition reactions. The study also explores the effect of co-calcination of Ag and γ-Al₂O₃, showing that high-temperature calcination can induce the formation of terminal hydroxyl groups and promote single-atom Ag dispersion. The findings provide insights into designing thermally stable single-atom catalysts by creating additional anchor points for Ag capture at high temperatures.