Improving the performance of Pt-H3PMo12O40 catalysts in the selective dehydrogenation of propane with O2 and H2

• Effective propane dehydrogenation at a low temperature with O2 and H2.
• Strong promoting effect of H3PO4 and Ag on catalytic properties of Pt-H3PMo12O40.
• Selectivity to propene up to 94%, propane conversion up to 7.5%.

The low-temperature dehydrogenation of propane with O2 and H2 on H3PMo12O40-modified Pt catalysts has been studied and improvement of the catalyst performance achieved with the aid of promoters and operating conditions. Introduction of phosphoric acid into the catalysts results in a more uniform distribution of heteropoly acid and enables the content of Pt to be decreased to 0.05 wt.% without affecting catalyst productivity at the low temperature (200 °C). With Ag as the promoter, the propane combustion to CO2 can be further lowered and selectivity to propene enhanced to 94%. The best results were obtained when the consumption of H2 and O2 along the catalyst bed was compensated with a new portion of the reagents (two reactors in line); propene selectivity was still near 90% at overall propane conversion of 7.5% and propene space-time yield of 370 g kgcat−1 h−1. The catalysts showed little deactivation and maintained their conversion and selectivity values for the time of the measurements (5–10 h).

Figure optionsDownload high-quality image (166 K)Download as PowerPoint slide