Fig. 4.
13C NMR studies of reaction using 13CO or 13CH4. 13C NMR spectra of products of acetic acid, formic acid, and methanol on 28 mg 0.10 wt%Rh/ZSM-5 at 170 °C for 10 h in gas of a mixture of 0.7 bar 13CO, 6.3 bar CO, 14 bar CH4, and 8 bar O2, b mixture of 7 bar CO, 14 bar CH4, and 8 bar O2, c mixture of 7 bar CO, 0.7 bar 13CH4, 13.3 bar CH4, and 8 bar O2, and d mixture of 7 bar CO, 14 bar CH4, and 8 bar O2. a and b are isotope experiments; c and d are their corresponding contrast experiments