Fig. 9: Trace of HCHO elements.
From: Insight into selectivity of photocatalytic methane oxidation to formaldehyde on tungsten trioxide
a GC-MS spectra of HCHO obtained in WO3{001} and WO3{110} system using 13CH4 as carbon isotope. b GC-MS spectra of HCHO obtained in WO3{001} system using 18O2 as oxygen isotope and the recycled WO3{001} as photocatalyst without O2 addition. c GC-MS spectra of HCHO obtained in WO3{110} system using 18O2 or H218O as oxygen isotope. d GC-MS spectra of HCHO obtained in WO3{001} system using H218O as oxygen isotope and the recycled WO3{001} as photocatalyst without O2 addition.
