Vapour phase carbonylation of methanol or dimethyl ether with metal-ion exchanged heteropoly acid catalysts

Abstract

Metal-ion exchanged heteropoly acids of the general formula M[W12P040] (M = a group Vlll metal) supported on S O 2 have been found to be excellent catalysts for the vapour phase carbonylation of methanol or dimethyl ether to methyl acetate at 225°C and 1 atm total operating pressure.

Dicarbonylrhodium(I) Complexes of Bipyridine Ligands with Proximate H‐Bonding Substituents and Their Application in Methyl Acetate Carbonylation

“…The 31 P NMR chemical shifts were referenced to H 3 PO 4 . The 19 F NMR chemical shifts were referenced to CFCl 3 . Mass spectra were recorded with either a VG Autospec or a VG Platform II spectrometer.…”

“…A standard nitrogen-filled glove box was used for any subsequent manipulation and storage of these compounds. Standard 1 H, 19 F, 31 P and 13 C NMR spectra were recorded with a Bruker AV-400 or DRX-400 spectrometer.…”

“…[18,20] Although these strong acids can carbonylate methanol without the presence of a transition metal, the selectivities are generally lower due to the formation of significant amounts of dimethyl ether. [19,21,22] The high temperatures and the strongly acidic reaction conditions required for methanol carbonylation, combined with the use of iodide as the co-catalyst, present significant challenges in terms of reactor engineering and corrosion prevention. Alternative catalysts that can operate under milder reaction conditions could significantly lower the cost of acetic acid production.…”

“…[8,[10][11][12][13][14] Alternative strategies for the activation of methanol have used strong acids such as zeolites, [15][16][17][18] heteropolyacids [19] and superacids. [20] These strong acids can protonate methanol, which upon elimination of H 2 O generates the carbenium cation, CH 3 + .…”

Carbonylation of Dimethyl Ether on Ag/ Cs1.5H1.5PW12O40: In-Situ FTIR Spectroscopy Study of the Ag-Carbonyls

“…Starting with Cu mordenite [3] BP Chemicals Limited continued their discoveries in halide-free DME carbonylation with other acidic zeolites -H-ZSM5, and H-FER [4]. Wegman was the first to demonstrate that rhodium or iridium salts of tungstophosphoric heteropoly acid supported on silica can catalyze DME carbonylation to methyl acetate [5]. We subsequently have shown that acidic cesium salts of 12-tungstophosphoric acid promoted with rhodium can lead to a 10-fold enhancement in the activity of halide-free DME carbonylation to methyl acetate [6].…”