Fig. 1: Structural characterization of the catalysts.

a Catalyst synthesis scheme, b XRD patterns, c Raman spectra of various catalysts, d In 3 d, e Zr 3 d and f O 1 s XPS of different catalysts.

a Catalyst synthesis scheme, b XRD patterns, c Raman spectra of various catalysts, d In 3 d, e Zr 3 d and f O 1 s XPS of different catalysts.