Bifunctional Organorhodium Solid Acid Catalysts for Methanol Carbonylation

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• 作者：Lee D. Dingwall ; Adam F. Lee ; Jason M. Lynam ; Karen Wilson ; Luca Olivi ; Jon M. S. Deeley ; Sander Gaemers ; Glenn J. Sunley
• 刊名：ACS Catalysis
• 出版年：2012
• 出版时间：July 6, 2012
• 年：2012
• 卷：2
• 期：7
• 页码：1368-1376
• 全文大小：449K
• 年卷期：v.2,no.7(July 6, 2012)
• ISSN：2155-5435

文摘

Robust, bifunctional catalysts comprising Rh(CO)(Xantphos) exchanged phosphotungstic acids of general formulas [Rh(CO)(Xantphos)]⁺_n[H_3鈥?i>nPW₁₂O₄₀]n鈭?/sup> have been synthesized over silica supports which exhibit tunable activity and selectivity toward direct vapor phase methanol carbonylation. The optimal Rh:acid ratio = 0.5, with higher rhodium concentrations increasing the selectivity to methyl acetate over dimethyl ether at the expense of lower acidity and poor activity. On-stream deactivation above 200 掳C reflects Rh decomplexation and reduction to Rh metal, in conjunction with catalyst dehydration and loss of solid acidity because of undesired methyl acetate hydrolysis, but can be alleviated by water addition and lower temperature operation.

Keywords:

rhodium; heteropoly acid; methanol; carbonylation; EXAFS