Preparation of Cu single atoms on N-doped carbon materials with supercritical CO2 deposition

•Cu single-atom on N-doped carbon materials by supercritical CO2 deposition.•N-doped carbon is a mesoporous material with a high surface area of 1301 m2/g.•Atomically dispersed metal atoms were prepared without further post-treatment.•AC-HAADF-STEM confirms that Cu atoms are equally dispersed over the NC support.•Cu-NC shows excellent performance in oxidation of benzyl alcohol to benzaldehyde.