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

Abstract

Coadsorbiertes Wasser bestimmt die Verteilung der Reaktionsprodukte bei der Carbonylierung von Isobutan an einem sulfatierten ZrO2‐Katalysator bei 70°C. Dies ist das Ergebnis von Festkörper‐13C‐NMR‐ (in situ) und hochauflösender 13C‐NMR‐Spektroskopie (ex situ) sowie GC‐MS‐Analysen. Bei wasserfreiem Arbeiten wird selektiv Methylisopropylketon gebildet, während in Gegenwart von coadsorbiertem Wasser Pivalinsäure als Hauptprodukt entsteht (siehe Schema).

Coupling Conversion of n-Hexane and CO over an HZSM-5 Zeolite: Tuning the H/C Balance and Achieving High Aromatic Selectivity

“…More interestingly, a new band at 1680 cm –1 attributed to the CO stretching mode of acyl species emerged at 210 °C, which is consistent with previous MAS NMR observations of 13 CO and small alkane coreaction systems. ,, These acyl species gradually disappeared when the temperature reached 340 °C, which demonstrates that carbon monoxide could react with carbonium ions to generate acyl species, and these acyl species could transform into other species at higher temperatures. In addition, a peak that might be due to the CO stretching vibration of a carbonate phase appeared at 1431 cm –1 with increasing temperature.…”

“…5 Stepanov and coworkers observed isobutane carbonylation with CO over sulfated zirconia using in situ NMR characterization. 6 Alkane carbonylation over a Zn-ZSM-5 zeolite was also observed by solid-state NMR. 7 In another related report, signals corresponding to carboxylic acids and alkanes were observed by solid-state NMR during the coreaction of CO, H 2 O, and propane or isobutane over an HZSM-5 zeolite.…”

“…It was reported that superacidic HF/SbF 5 and/or CF 3 SO 3 H/SbF 5 could catalyze alkane carbonylation to form carboxylic acids, aldehydes, or ketones . Stepanov and co-workers observed isobutane carbonylation with CO over sulfated zirconia using in situ NMR characterization . Alkane carbonylation over a Zn-ZSM-5 zeolite was also observed by solid-state NMR .…”

NMR‐Spectroscopic Evidence of Intermediate‐Dependent Pathways for Acetic Acid Formation from Methane and Carbon Monoxide over a ZnZSM‐5 Zeolite Catalyst

“…Since the pioneering work of Sen and Lin [5] and Fujiwara and coworkers [6] who found that acetic acid can be produced directly by carbonylation of methane with CO in a homogenous catalysis system, considerable efforts have been devoted to the direct strategy. [12] Moreover, promising potential has been demonstrated for the conversion of methane into acetic acid and derivatives over Rhdoped FePO 4 [13] and sulfated zirconia solid catalysts. The carbonylation of isobutane was the first reported example for the conversion of saturated alkanes to produce ketone and carboxylic acid on environmentally friendly heterogeneous solid catalysts.…”