Partial Oxidation of Lower Alkanes over Polyoxometallate Catalysts

摘要

The substitution of abundant, low-cost alkane feedstocks for the relatively costly olefin feedstocks currently used to produce high-value oxygenated organics would provide a significant competitive advantage to manufacturers. However, very few catalysts can produce these chemicals cost-effectively from the relatively unreactive starting materials. Rohm and Haas Company and Sun Company, Inc., in partnership with the NIST Advanced Technology Program (1), have been conducting a project aimed at the development of new catalyst technology for the single-step oxidation of light alkanes, such as propane and isobutane, to oxygenated chemical intermediates, such as acrylic acid and methacrylic acid. This paper describes the synthesis and catalytic activity of modified Keggin-type polyoxometallate compounds. The heterogeneous catalysts are prepared by a synthesis procedure that produces structures wit improved catalytic performance compared to analogs prepared by conventional methods. The improved product selectivities and yields can be mainly attributed to careful control of the catalyst pore size and pore size distribution. In addition, the procedure described leads to better batch-to-batch catalyst reproducibility.