Alkane Carbonylation with Carbon Monoxide on Sulfated Zirconia: NMR Observation of Ketone and Carboxylic Acid Formation from Isobutane and CO

Coadsorbed water determines the reaction products when isobutane undergoes carbonylation by CO on a sulfated zirconia catalyst at 70°C. This is shown by the results of in situ solid-state 13C NMR and ex situ 13C high-resolution NMR spectroscopy and by GC-MS analyses. Methyl isopropyl ketone selectively forms in the absence of water, while pivalic acid represents the primary reaction product the presence of coadsorbed water (see scheme).