Sodium Acrylate from Ethylene and CO2: The Path from Basic Research to a System Appropriate for a Continuous Process

Sodium acrylate is a valuable monomer for the synthesis of superabsorbents and produced industrially on large scale. Currently, sodium acrylate is made by the oxidation of propene to acrylic acid followed by neutralization with NaOH. The synthesis of sodium acrylate from CO2, ethylene, and NaOH would be very attractive due to lower raw material costs but was for many years only a “dream reaction.” Significant progress has been made since the first report in 2012 on a catalytic system for this synthesis. Different nickel and palladium catalysts were identified. In addition, the influence of the base in this reaction was evaluated. The use of solvents fulfilling certain criteria is necessary for the design of continuous process concepts. To date, two process concepts have resulted: one using phenolate bases and the other utilizing alkoxide bases.