Impact of platinum loading and dispersion on the catalytic activity of Pt/SnO2 and Pt/α-Fe2O3

•Platinum was mechanochemically dispersed over reducible SnO2 and α-Fe2O3 supports.•PtNPs in the range of 1.0–1.3 nm are well-dispersed on the SnO2 and α-Fe2O3.•Small STEM spots with a size of 0.1 nm indicate atomically dispersed Pt on the SnO2.•The Pt on SnO2 and Fe2O3 shows high catalytic activity for reduction of 4-NP to 4-AP.