Electrooxidation of Propylene to Acrolein

Abstract

Short chain alkanes and alkenes (C1-4) typically have little economic value and are difficult to transport since they are gases. Because of this, these hydrocarbons are of so low value that they are often flared during extraction of oil.1 This talk investigates electrochemically partially oxidizing these materials to high-value liquid products, thus increasing both the value and ease in transportation. If the oxidation is cathodic enough (< ~ +0.9 V vs. RHE) this can be combined with a standard oxygen reduction reaction cathode in a PEM fuel cell type approach to produce a device that does not consume electrical power, but actually has the potential to produce a small amount of power.2 Specifically this talk focuses on partial electrochemical oxidation of propylene to a variety of high value products such as acrolein, propylene oxide, propylene glycol, and acrylic acid and low value products such as CO2, and acetic acid. Using a Pd catalyst, we analyse the effects of pre-treatment, potential, pH and other factors in optimizing high value products while minimizing low value products. As shown below, one of the most promising findings is a high degree of acrolein selectivity at 0.9 V vs RHE in acidic solutions. The figure below shows that we can achieve stable electrochemical oxidation of propylene for 1 hour and produce acrolein with a selectivity of near 80%. Elvidge, C. D.; Ziskin, D.; Baugh, K. E.; Tuttle, B. T.; Ghosh, T.; Pack, D. W.; Erwin, E. H.; Zhizhin, M., A Fifteen Year Record of Global Natural Gas Flaring Derived from Satellite Data. Energies 2009, 2 (3), 595-622.Yamanaka, I., Active control of catalysis and product selectivity by a fuel cell system. Research on Chemical Intermediates 2006, 32 (3-4), 373-38 Figure 1